2102 lines
55 KiB
C
2102 lines
55 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Mini less implementation for busybox
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*
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* Copyright (C) 2005 by Rob Sullivan <cogito.ergo.cogito@gmail.com>
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
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/*
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* TODO:
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* - Add more regular expression support - search modifiers, certain matches, etc.
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* - Add more complex bracket searching - currently, nested brackets are
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* not considered.
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* - Add support for "F" as an input. This causes less to act in
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* a similar way to tail -f.
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* - Allow horizontal scrolling.
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*
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* Notes:
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* - the inp file pointer is used so that keyboard input works after
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* redirected input has been read from stdin
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*/
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//config:config LESS
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//config: bool "less"
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//config: default y
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//config: help
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//config: 'less' is a pager, meaning that it displays text files. It possesses
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//config: a wide array of features, and is an improvement over 'more'.
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//config:
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//config:config FEATURE_LESS_MAXLINES
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//config: int "Max number of input lines less will try to eat"
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//config: default 9999999
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//config: depends on LESS
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//config:
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//config:config FEATURE_LESS_BRACKETS
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//config: bool "Enable bracket searching"
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//config: default y
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//config: depends on LESS
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//config: help
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//config: This option adds the capability to search for matching left and right
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//config: brackets, facilitating programming.
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//config:
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//config:config FEATURE_LESS_FLAGS
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//config: bool "Enable -m/-M"
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//config: default y
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//config: depends on LESS
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//config: help
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//config: The -M/-m flag enables a more sophisticated status line.
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//config:
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//config:config FEATURE_LESS_TRUNCATE
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//config: bool "Enable -S"
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//config: default y
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//config: depends on LESS
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//config: help
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//config: The -S flag causes long lines to be truncated rather than
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//config: wrapped.
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//config:
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//config:config FEATURE_LESS_MARKS
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//config: bool "Enable marks"
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//config: default y
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//config: depends on LESS
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//config: help
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//config: Marks enable positions in a file to be stored for easy reference.
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//config:
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//config:config FEATURE_LESS_REGEXP
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//config: bool "Enable regular expressions"
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//config: default y
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//config: depends on LESS
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//config: help
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//config: Enable regular expressions, allowing complex file searches.
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//config:
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//config:config FEATURE_LESS_WINCH
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//config: bool "Enable automatic resizing on window size changes"
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//config: default y
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//config: depends on LESS
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//config: help
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//config: Makes less track window size changes.
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//config:
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//config:config FEATURE_LESS_ASK_TERMINAL
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//config: bool "Use 'tell me cursor position' ESC sequence to measure window"
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//config: default y
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//config: depends on FEATURE_LESS_WINCH
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//config: help
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//config: Makes less track window size changes.
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//config: If terminal size can't be retrieved and $LINES/$COLUMNS are not set,
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//config: this option makes less perform a last-ditch effort to find it:
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//config: position cursor to 999,999 and ask terminal to report real
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//config: cursor position using "ESC [ 6 n" escape sequence, then read stdin.
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//config:
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//config: This is not clean but helps a lot on serial lines and such.
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//config:
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//config:config FEATURE_LESS_DASHCMD
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//config: bool "Enable flag changes ('-' command)"
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//config: default y
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//config: depends on LESS
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//config: help
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//config: This enables the ability to change command-line flags within
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//config: less itself ('-' keyboard command).
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//config:
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//config:config FEATURE_LESS_LINENUMS
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//config: bool "Enable dynamic switching of line numbers"
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//config: default y
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//config: depends on FEATURE_LESS_DASHCMD
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//config: help
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//config: Enables "-N" command.
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//applet:IF_LESS(APPLET(less, BB_DIR_USR_BIN, BB_SUID_DROP))
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//kbuild:lib-$(CONFIG_LESS) += less.o
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//usage:#define less_trivial_usage
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//usage: "[-E" IF_FEATURE_LESS_REGEXP("I")IF_FEATURE_LESS_FLAGS("Mm")
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//usage: "N" IF_FEATURE_LESS_TRUNCATE("S") "h~] [FILE]..."
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//usage:#define less_full_usage "\n\n"
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//usage: "View FILE (or stdin) one screenful at a time\n"
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//usage: "\n -E Quit once the end of a file is reached"
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//usage: IF_FEATURE_LESS_REGEXP(
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//usage: "\n -I Ignore case in all searches"
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//usage: )
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//usage: IF_FEATURE_LESS_FLAGS(
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//usage: "\n -M,-m Display status line with line numbers"
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//usage: "\n and percentage through the file"
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//usage: )
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//usage: "\n -N Prefix line number to each line"
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//usage: IF_FEATURE_LESS_TRUNCATE(
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//usage: "\n -S Truncate long lines"
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//usage: )
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//usage: "\n -~ Suppress ~s displayed past EOF"
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#include <sched.h> /* sched_yield() */
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#include "libbb.h"
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#include "common_bufsiz.h"
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#if ENABLE_FEATURE_LESS_REGEXP
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#include "xregex.h"
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#endif
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#define ESC "\033"
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/* The escape codes for highlighted and normal text */
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#define HIGHLIGHT ESC"[7m"
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#define NORMAL ESC"[0m"
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/* The escape code to home and clear to the end of screen */
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#define CLEAR ESC"[H\033[J"
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/* The escape code to clear to the end of line */
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#define CLEAR_2_EOL ESC"[K"
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enum {
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/* Absolute max of lines eaten */
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MAXLINES = CONFIG_FEATURE_LESS_MAXLINES,
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/* This many "after the end" lines we will show (at max) */
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TILDES = 1,
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};
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/* Command line options */
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enum {
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FLAG_E = 1 << 0,
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FLAG_M = 1 << 1,
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FLAG_m = 1 << 2,
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FLAG_N = 1 << 3,
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FLAG_TILDE = 1 << 4,
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FLAG_I = 1 << 5,
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FLAG_S = (1 << 6) * ENABLE_FEATURE_LESS_TRUNCATE,
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/* hijack command line options variable for internal state vars */
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LESS_STATE_MATCH_BACKWARDS = 1 << 15,
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};
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#if !ENABLE_FEATURE_LESS_REGEXP
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enum { pattern_valid = 0 };
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#endif
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struct globals {
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int cur_fline; /* signed */
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int kbd_fd; /* fd to get input from */
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int kbd_fd_orig_flags;
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int less_gets_pos;
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/* last position in last line, taking into account tabs */
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size_t last_line_pos;
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unsigned max_fline;
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unsigned max_lineno; /* this one tracks linewrap */
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unsigned max_displayed_line;
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unsigned width;
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#if ENABLE_FEATURE_LESS_WINCH
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unsigned winch_counter;
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#endif
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ssize_t eof_error; /* eof if 0, error if < 0 */
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ssize_t readpos;
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ssize_t readeof; /* must be signed */
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const char **buffer;
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const char **flines;
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const char *empty_line_marker;
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unsigned num_files;
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unsigned current_file;
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char *filename;
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char **files;
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#if ENABLE_FEATURE_LESS_FLAGS
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int num_lines; /* a flag if < 0, line count if >= 0 */
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# define REOPEN_AND_COUNT (-1)
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# define REOPEN_STDIN (-2)
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# define NOT_REGULAR_FILE (-3)
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#endif
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#if ENABLE_FEATURE_LESS_MARKS
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unsigned num_marks;
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unsigned mark_lines[15][2];
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#endif
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#if ENABLE_FEATURE_LESS_REGEXP
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unsigned *match_lines;
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int match_pos; /* signed! */
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int wanted_match; /* signed! */
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int num_matches;
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regex_t pattern;
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smallint pattern_valid;
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#endif
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#if ENABLE_FEATURE_LESS_ASK_TERMINAL
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smallint winsize_err;
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#endif
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smallint terminated;
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struct termios term_orig, term_less;
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char kbd_input[KEYCODE_BUFFER_SIZE];
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};
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#define G (*ptr_to_globals)
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#define cur_fline (G.cur_fline )
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#define kbd_fd (G.kbd_fd )
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#define less_gets_pos (G.less_gets_pos )
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#define last_line_pos (G.last_line_pos )
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#define max_fline (G.max_fline )
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#define max_lineno (G.max_lineno )
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#define max_displayed_line (G.max_displayed_line)
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#define width (G.width )
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#define winch_counter (G.winch_counter )
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/* This one is 100% not cached by compiler on read access */
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#define WINCH_COUNTER (*(volatile unsigned *)&winch_counter)
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#define eof_error (G.eof_error )
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#define readpos (G.readpos )
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#define readeof (G.readeof )
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#define buffer (G.buffer )
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#define flines (G.flines )
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#define empty_line_marker (G.empty_line_marker )
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#define num_files (G.num_files )
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#define current_file (G.current_file )
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#define filename (G.filename )
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#define files (G.files )
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#define num_lines (G.num_lines )
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#define num_marks (G.num_marks )
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#define mark_lines (G.mark_lines )
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#if ENABLE_FEATURE_LESS_REGEXP
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#define match_lines (G.match_lines )
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#define match_pos (G.match_pos )
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#define num_matches (G.num_matches )
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#define wanted_match (G.wanted_match )
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#define pattern (G.pattern )
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#define pattern_valid (G.pattern_valid )
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#endif
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#define terminated (G.terminated )
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#define term_orig (G.term_orig )
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#define term_less (G.term_less )
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#define kbd_input (G.kbd_input )
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#define INIT_G() do { \
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SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
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less_gets_pos = -1; \
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empty_line_marker = "~"; \
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num_files = 1; \
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current_file = 1; \
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eof_error = 1; \
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terminated = 1; \
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IF_FEATURE_LESS_REGEXP(wanted_match = -1;) \
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} while (0)
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/* flines[] are lines read from stdin, each in malloc'ed buffer.
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* Line numbers are stored as uint32_t prepended to each line.
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* Pointer is adjusted so that flines[i] points directly past
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* line number. Accesor: */
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#define MEMPTR(p) ((char*)(p) - 4)
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#define LINENO(p) (*(uint32_t*)((p) - 4))
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/* Reset terminal input to normal */
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static void set_tty_cooked(void)
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{
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fflush_all();
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tcsetattr(kbd_fd, TCSANOW, &term_orig);
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}
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/* Move the cursor to a position (x,y), where (0,0) is the
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top-left corner of the console */
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static void move_cursor(int line, int row)
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{
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printf(ESC"[%u;%uH", line, row);
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}
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static void clear_line(void)
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{
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printf(ESC"[%u;0H" CLEAR_2_EOL, max_displayed_line + 2);
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}
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static void print_hilite(const char *str)
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{
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printf(HIGHLIGHT"%s"NORMAL, str);
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}
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static void print_statusline(const char *str)
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{
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clear_line();
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printf(HIGHLIGHT"%.*s"NORMAL, width - 1, str);
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}
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/* Exit the program gracefully */
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static void less_exit(int code)
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{
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set_tty_cooked();
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if (!(G.kbd_fd_orig_flags & O_NONBLOCK))
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ndelay_off(kbd_fd);
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clear_line();
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if (code < 0)
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kill_myself_with_sig(- code); /* does not return */
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exit(code);
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}
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#if (ENABLE_FEATURE_LESS_DASHCMD && ENABLE_FEATURE_LESS_LINENUMS) \
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|| ENABLE_FEATURE_LESS_WINCH
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static void re_wrap(void)
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{
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int w = width;
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int new_line_pos;
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int src_idx;
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int dst_idx;
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int new_cur_fline = 0;
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uint32_t lineno;
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char linebuf[w + 1];
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const char **old_flines = flines;
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const char *s;
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char **new_flines = NULL;
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char *d;
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if (option_mask32 & FLAG_N)
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w -= 8;
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src_idx = 0;
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dst_idx = 0;
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s = old_flines[0];
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lineno = LINENO(s);
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d = linebuf;
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new_line_pos = 0;
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while (1) {
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*d = *s;
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if (*d != '\0') {
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new_line_pos++;
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if (*d == '\t') { /* tab */
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new_line_pos += 7;
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new_line_pos &= (~7);
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}
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s++;
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d++;
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if (new_line_pos >= w) {
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int sz;
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/* new line is full, create next one */
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*d = '\0';
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next_new:
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sz = (d - linebuf) + 1; /* + 1: NUL */
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d = ((char*)xmalloc(sz + 4)) + 4;
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LINENO(d) = lineno;
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memcpy(d, linebuf, sz);
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new_flines = xrealloc_vector(new_flines, 8, dst_idx);
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new_flines[dst_idx] = d;
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dst_idx++;
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if (new_line_pos < w) {
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/* if we came here thru "goto next_new" */
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if (src_idx > max_fline)
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break;
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lineno = LINENO(s);
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}
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d = linebuf;
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new_line_pos = 0;
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}
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continue;
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}
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/* *d == NUL: old line ended, go to next old one */
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free(MEMPTR(old_flines[src_idx]));
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/* btw, convert cur_fline... */
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if (cur_fline == src_idx)
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new_cur_fline = dst_idx;
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src_idx++;
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/* no more lines? finish last new line (and exit the loop) */
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if (src_idx > max_fline)
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goto next_new;
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s = old_flines[src_idx];
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if (lineno != LINENO(s)) {
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/* this is not a continuation line!
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* create next _new_ line too */
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goto next_new;
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}
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}
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free(old_flines);
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flines = (const char **)new_flines;
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max_fline = dst_idx - 1;
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last_line_pos = new_line_pos;
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cur_fline = new_cur_fline;
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/* max_lineno is screen-size independent */
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#if ENABLE_FEATURE_LESS_REGEXP
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pattern_valid = 0;
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#endif
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}
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#endif
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#if ENABLE_FEATURE_LESS_REGEXP
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static void fill_match_lines(unsigned pos);
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#else
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#define fill_match_lines(pos) ((void)0)
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#endif
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static int at_end(void)
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{
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return (option_mask32 & FLAG_S)
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? !(cur_fline <= max_fline &&
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max_lineno > LINENO(flines[cur_fline]) + max_displayed_line)
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: !(max_fline > cur_fline + max_displayed_line);
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}
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/* Devilishly complex routine.
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*
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* Has to deal with EOF and EPIPE on input,
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* with line wrapping, with last line not ending in '\n'
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* (possibly not ending YET!), with backspace and tabs.
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* It reads input again if last time we got an EOF (thus supporting
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* growing files) or EPIPE (watching output of slow process like make).
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*
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* Variables used:
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* flines[] - array of lines already read. Linewrap may cause
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* one source file line to occupy several flines[n].
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* flines[max_fline] - last line, possibly incomplete.
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* terminated - 1 if flines[max_fline] is 'terminated'
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* (if there was '\n' [which isn't stored itself, we just remember
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* that it was seen])
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* max_lineno - last line's number, this one doesn't increment
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* on line wrap, only on "real" new lines.
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* readbuf[0..readeof-1] - small preliminary buffer.
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* readbuf[readpos] - next character to add to current line.
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* last_line_pos - screen line position of next char to be read
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* (takes into account tabs and backspaces)
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* eof_error - < 0 error, == 0 EOF, > 0 not EOF/error
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*
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* "git log -p | less -m" on the kernel git tree is a good test for EAGAINs,
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* "/search on very long input" and "reaching max line count" corner cases.
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*/
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static void read_lines(void)
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{
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char *current_line, *p;
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int w = width;
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char last_terminated = terminated;
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time_t last_time = 0;
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int retry_EAGAIN = 2;
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#if ENABLE_FEATURE_LESS_REGEXP
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unsigned old_max_fline = max_fline;
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#endif
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#define readbuf bb_common_bufsiz1
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setup_common_bufsiz();
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/* (careful: max_fline can be -1) */
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if (max_fline + 1 > MAXLINES)
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return;
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if (option_mask32 & FLAG_N)
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w -= 8;
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p = current_line = ((char*)xmalloc(w + 5)) + 4;
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if (!last_terminated) {
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const char *cp = flines[max_fline];
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p = stpcpy(p, cp);
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free(MEMPTR(cp));
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/* last_line_pos is still valid from previous read_lines() */
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} else {
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max_fline++;
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last_line_pos = 0;
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}
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while (1) { /* read lines until we reach cur_fline or wanted_match */
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*p = '\0';
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terminated = 0;
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while (1) { /* read chars until we have a line */
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char c;
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/* if no unprocessed chars left, eat more */
|
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if (readpos >= readeof) {
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int flags = ndelay_on(0);
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while (1) {
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|
time_t t;
|
|
|
|
errno = 0;
|
|
eof_error = safe_read(STDIN_FILENO, readbuf, COMMON_BUFSIZE);
|
|
if (errno != EAGAIN)
|
|
break;
|
|
t = time(NULL);
|
|
if (t != last_time) {
|
|
last_time = t;
|
|
if (--retry_EAGAIN < 0)
|
|
break;
|
|
}
|
|
sched_yield();
|
|
}
|
|
fcntl(0, F_SETFL, flags); /* ndelay_off(0) */
|
|
readpos = 0;
|
|
readeof = eof_error;
|
|
if (eof_error <= 0)
|
|
goto reached_eof;
|
|
retry_EAGAIN = 1;
|
|
}
|
|
c = readbuf[readpos];
|
|
/* backspace? [needed for manpages] */
|
|
/* <tab><bs> is (a) insane and */
|
|
/* (b) harder to do correctly, so we refuse to do it */
|
|
if (c == '\x8' && last_line_pos && p[-1] != '\t') {
|
|
readpos++; /* eat it */
|
|
last_line_pos--;
|
|
/* was buggy (p could end up <= current_line)... */
|
|
*--p = '\0';
|
|
continue;
|
|
}
|
|
{
|
|
size_t new_last_line_pos = last_line_pos + 1;
|
|
if (c == '\t') {
|
|
new_last_line_pos += 7;
|
|
new_last_line_pos &= (~7);
|
|
}
|
|
if ((int)new_last_line_pos > w)
|
|
break;
|
|
last_line_pos = new_last_line_pos;
|
|
}
|
|
/* ok, we will eat this char */
|
|
readpos++;
|
|
if (c == '\n') {
|
|
terminated = 1;
|
|
last_line_pos = 0;
|
|
break;
|
|
}
|
|
/* NUL is substituted by '\n'! */
|
|
if (c == '\0') c = '\n';
|
|
*p++ = c;
|
|
*p = '\0';
|
|
} /* end of "read chars until we have a line" loop */
|
|
#if 0
|
|
//BUG: also triggers on this:
|
|
// { printf "\nfoo\n"; sleep 1; printf "\nbar\n"; } | less
|
|
// (resulting in lost empty line between "foo" and "bar" lines)
|
|
// the "terminated" logic needs fixing (or explaining)
|
|
/* Corner case: linewrap with only "" wrapping to next line */
|
|
/* Looks ugly on screen, so we do not store this empty line */
|
|
if (!last_terminated && !current_line[0]) {
|
|
last_terminated = 1;
|
|
max_lineno++;
|
|
continue;
|
|
}
|
|
#endif
|
|
reached_eof:
|
|
last_terminated = terminated;
|
|
flines = xrealloc_vector(flines, 8, max_fline);
|
|
|
|
flines[max_fline] = (char*)xrealloc(MEMPTR(current_line), strlen(current_line) + 1 + 4) + 4;
|
|
LINENO(flines[max_fline]) = max_lineno;
|
|
if (terminated)
|
|
max_lineno++;
|
|
|
|
if (max_fline >= MAXLINES) {
|
|
eof_error = 0; /* Pretend we saw EOF */
|
|
break;
|
|
}
|
|
if (!at_end()) {
|
|
#if !ENABLE_FEATURE_LESS_REGEXP
|
|
break;
|
|
#else
|
|
if (wanted_match >= num_matches) { /* goto_match called us */
|
|
fill_match_lines(old_max_fline);
|
|
old_max_fline = max_fline;
|
|
}
|
|
if (wanted_match < num_matches)
|
|
break;
|
|
#endif
|
|
}
|
|
if (eof_error <= 0) {
|
|
break;
|
|
}
|
|
max_fline++;
|
|
current_line = ((char*)xmalloc(w + 5)) + 4;
|
|
p = current_line;
|
|
last_line_pos = 0;
|
|
} /* end of "read lines until we reach cur_fline" loop */
|
|
|
|
if (eof_error < 0) {
|
|
if (errno == EAGAIN) {
|
|
eof_error = 1;
|
|
} else {
|
|
print_statusline(bb_msg_read_error);
|
|
}
|
|
}
|
|
#if ENABLE_FEATURE_LESS_FLAGS
|
|
else if (eof_error == 0)
|
|
num_lines = max_lineno;
|
|
#endif
|
|
|
|
fill_match_lines(old_max_fline);
|
|
#if ENABLE_FEATURE_LESS_REGEXP
|
|
/* prevent us from being stuck in search for a match */
|
|
wanted_match = -1;
|
|
#endif
|
|
#undef readbuf
|
|
}
|
|
|
|
#if ENABLE_FEATURE_LESS_FLAGS
|
|
static int safe_lineno(int fline)
|
|
{
|
|
if (fline >= max_fline)
|
|
fline = max_fline - 1;
|
|
|
|
/* also catches empty file (max_fline == 0) */
|
|
if (fline < 0)
|
|
return 0;
|
|
|
|
return LINENO(flines[fline]) + 1;
|
|
}
|
|
|
|
/* count number of lines in file */
|
|
static void update_num_lines(void)
|
|
{
|
|
int count, fd;
|
|
struct stat stbuf;
|
|
ssize_t len, i;
|
|
char buf[4096];
|
|
|
|
/* only do this for regular files */
|
|
if (num_lines == REOPEN_AND_COUNT || num_lines == REOPEN_STDIN) {
|
|
count = 0;
|
|
fd = open("/proc/self/fd/0", O_RDONLY);
|
|
if (fd < 0 && num_lines == REOPEN_AND_COUNT) {
|
|
/* "filename" is valid only if REOPEN_AND_COUNT */
|
|
fd = open(filename, O_RDONLY);
|
|
}
|
|
if (fd < 0) {
|
|
/* somebody stole my file! */
|
|
num_lines = NOT_REGULAR_FILE;
|
|
return;
|
|
}
|
|
if (fstat(fd, &stbuf) != 0 || !S_ISREG(stbuf.st_mode)) {
|
|
num_lines = NOT_REGULAR_FILE;
|
|
goto do_close;
|
|
}
|
|
while ((len = safe_read(fd, buf, sizeof(buf))) > 0) {
|
|
for (i = 0; i < len; ++i) {
|
|
if (buf[i] == '\n' && ++count == MAXLINES)
|
|
goto done;
|
|
}
|
|
}
|
|
done:
|
|
num_lines = count;
|
|
do_close:
|
|
close(fd);
|
|
}
|
|
}
|
|
|
|
/* Print a status line if -M was specified */
|
|
static void m_status_print(void)
|
|
{
|
|
int first, last;
|
|
unsigned percent;
|
|
|
|
if (less_gets_pos >= 0) /* don't touch statusline while input is done! */
|
|
return;
|
|
|
|
clear_line();
|
|
printf(HIGHLIGHT"%s", filename);
|
|
if (num_files > 1)
|
|
printf(" (file %i of %i)", current_file, num_files);
|
|
|
|
first = safe_lineno(cur_fline);
|
|
last = (option_mask32 & FLAG_S)
|
|
? MIN(first + max_displayed_line, max_lineno)
|
|
: safe_lineno(cur_fline + max_displayed_line);
|
|
printf(" lines %i-%i", first, last);
|
|
|
|
update_num_lines();
|
|
if (num_lines >= 0)
|
|
printf("/%i", num_lines);
|
|
|
|
if (at_end()) {
|
|
printf(" (END)");
|
|
if (num_files > 1 && current_file != num_files)
|
|
printf(" - next: %s", files[current_file]);
|
|
} else if (num_lines > 0) {
|
|
percent = (100 * last + num_lines/2) / num_lines;
|
|
printf(" %i%%", percent <= 100 ? percent : 100);
|
|
}
|
|
printf(NORMAL);
|
|
}
|
|
#endif
|
|
|
|
/* Print the status line */
|
|
static void status_print(void)
|
|
{
|
|
const char *p;
|
|
|
|
if (less_gets_pos >= 0) /* don't touch statusline while input is done! */
|
|
return;
|
|
|
|
/* Change the status if flags have been set */
|
|
#if ENABLE_FEATURE_LESS_FLAGS
|
|
if (option_mask32 & (FLAG_M|FLAG_m)) {
|
|
m_status_print();
|
|
return;
|
|
}
|
|
/* No flags set */
|
|
#endif
|
|
|
|
clear_line();
|
|
if (cur_fline && !at_end()) {
|
|
bb_putchar(':');
|
|
return;
|
|
}
|
|
p = "(END)";
|
|
if (!cur_fline)
|
|
p = filename;
|
|
if (num_files > 1) {
|
|
printf(HIGHLIGHT"%s (file %i of %i)"NORMAL,
|
|
p, current_file, num_files);
|
|
return;
|
|
}
|
|
print_hilite(p);
|
|
}
|
|
|
|
static const char controls[] ALIGN1 =
|
|
/* NUL: never encountered; TAB: not converted */
|
|
/**/"\x01\x02\x03\x04\x05\x06\x07\x08" "\x0a\x0b\x0c\x0d\x0e\x0f"
|
|
"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
|
|
"\x7f\x9b"; /* DEL and infamous Meta-ESC :( */
|
|
static const char ctrlconv[] ALIGN1 =
|
|
/* why 40 instead of 4a below? - it is a replacement for '\n'.
|
|
* '\n' is a former NUL - we subst it with @, not J */
|
|
"\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x40\x4b\x4c\x4d\x4e\x4f"
|
|
"\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f";
|
|
|
|
static void print_lineno(const char *line)
|
|
{
|
|
const char *fmt = " ";
|
|
unsigned n = n; /* for compiler */
|
|
|
|
if (line != empty_line_marker) {
|
|
/* Width of 7 preserves tab spacing in the text */
|
|
fmt = "%7u ";
|
|
n = LINENO(line) + 1;
|
|
if (n > 9999999 && MAXLINES > 9999999) {
|
|
n %= 10000000;
|
|
fmt = "%07u ";
|
|
}
|
|
}
|
|
printf(fmt, n);
|
|
}
|
|
|
|
|
|
#if ENABLE_FEATURE_LESS_REGEXP
|
|
static void print_found(const char *line)
|
|
{
|
|
int match_status;
|
|
int eflags;
|
|
char *growline;
|
|
regmatch_t match_structs;
|
|
|
|
char buf[width+1];
|
|
const char *str = line;
|
|
char *p = buf;
|
|
size_t n;
|
|
|
|
while (*str) {
|
|
n = strcspn(str, controls);
|
|
if (n) {
|
|
if (!str[n]) break;
|
|
memcpy(p, str, n);
|
|
p += n;
|
|
str += n;
|
|
}
|
|
n = strspn(str, controls);
|
|
memset(p, '.', n);
|
|
p += n;
|
|
str += n;
|
|
}
|
|
strcpy(p, str);
|
|
|
|
/* buf[] holds quarantined version of str */
|
|
|
|
/* Each part of the line that matches has the HIGHLIGHT
|
|
* and NORMAL escape sequences placed around it.
|
|
* NB: we regex against line, but insert text
|
|
* from quarantined copy (buf[]) */
|
|
str = buf;
|
|
growline = NULL;
|
|
eflags = 0;
|
|
goto start;
|
|
|
|
while (match_status == 0) {
|
|
char *new = xasprintf("%s%.*s"HIGHLIGHT"%.*s"NORMAL,
|
|
growline ? growline : "",
|
|
(int)match_structs.rm_so, str,
|
|
(int)(match_structs.rm_eo - match_structs.rm_so),
|
|
str + match_structs.rm_so);
|
|
free(growline);
|
|
growline = new;
|
|
str += match_structs.rm_eo;
|
|
line += match_structs.rm_eo;
|
|
eflags = REG_NOTBOL;
|
|
start:
|
|
/* Most of the time doesn't find the regex, optimize for that */
|
|
match_status = regexec(&pattern, line, 1, &match_structs, eflags);
|
|
/* if even "" matches, treat it as "not a match" */
|
|
if (match_structs.rm_so >= match_structs.rm_eo)
|
|
match_status = 1;
|
|
}
|
|
|
|
printf("%s%s\n", growline ? growline : "", str);
|
|
free(growline);
|
|
}
|
|
#else
|
|
void print_found(const char *line);
|
|
#endif
|
|
|
|
static void print_ascii(const char *str)
|
|
{
|
|
char buf[width+1];
|
|
char *p;
|
|
size_t n;
|
|
|
|
while (*str) {
|
|
n = strcspn(str, controls);
|
|
if (n) {
|
|
if (!str[n]) break;
|
|
printf("%.*s", (int) n, str);
|
|
str += n;
|
|
}
|
|
n = strspn(str, controls);
|
|
p = buf;
|
|
do {
|
|
if (*str == 0x7f)
|
|
*p++ = '?';
|
|
else if (*str == (char)0x9b)
|
|
/* VT100's CSI, aka Meta-ESC. Who's inventor? */
|
|
/* I want to know who committed this sin */
|
|
*p++ = '{';
|
|
else
|
|
*p++ = ctrlconv[(unsigned char)*str];
|
|
str++;
|
|
} while (--n);
|
|
*p = '\0';
|
|
print_hilite(buf);
|
|
}
|
|
puts(str);
|
|
}
|
|
|
|
/* Print the buffer */
|
|
static void buffer_print(void)
|
|
{
|
|
unsigned i;
|
|
|
|
move_cursor(0, 0);
|
|
for (i = 0; i <= max_displayed_line; i++) {
|
|
printf(CLEAR_2_EOL);
|
|
if (option_mask32 & FLAG_N)
|
|
print_lineno(buffer[i]);
|
|
if (pattern_valid)
|
|
print_found(buffer[i]);
|
|
else
|
|
print_ascii(buffer[i]);
|
|
}
|
|
if ((option_mask32 & FLAG_E)
|
|
&& eof_error <= 0
|
|
&& (max_fline - cur_fline) <= max_displayed_line
|
|
) {
|
|
less_exit(EXIT_SUCCESS);
|
|
}
|
|
status_print();
|
|
}
|
|
|
|
static void buffer_fill_and_print(void)
|
|
{
|
|
unsigned i;
|
|
#if ENABLE_FEATURE_LESS_TRUNCATE
|
|
int fpos = cur_fline;
|
|
|
|
if (option_mask32 & FLAG_S) {
|
|
/* Go back to the beginning of this line */
|
|
while (fpos && LINENO(flines[fpos]) == LINENO(flines[fpos-1]))
|
|
fpos--;
|
|
}
|
|
|
|
i = 0;
|
|
while (i <= max_displayed_line && fpos <= max_fline) {
|
|
int lineno = LINENO(flines[fpos]);
|
|
buffer[i] = flines[fpos];
|
|
i++;
|
|
do {
|
|
fpos++;
|
|
} while ((fpos <= max_fline)
|
|
&& (option_mask32 & FLAG_S)
|
|
&& lineno == LINENO(flines[fpos])
|
|
);
|
|
}
|
|
#else
|
|
for (i = 0; i <= max_displayed_line && cur_fline + i <= max_fline; i++) {
|
|
buffer[i] = flines[cur_fline + i];
|
|
}
|
|
#endif
|
|
for (; i <= max_displayed_line; i++) {
|
|
buffer[i] = empty_line_marker;
|
|
}
|
|
buffer_print();
|
|
}
|
|
|
|
/* move cur_fline to a given line number, reading lines if necessary */
|
|
static void goto_lineno(int target)
|
|
{
|
|
if (target <= 0 ) {
|
|
cur_fline = 0;
|
|
}
|
|
else if (target > LINENO(flines[cur_fline])) {
|
|
retry:
|
|
while (LINENO(flines[cur_fline]) != target && cur_fline < max_fline)
|
|
++cur_fline;
|
|
/* target not reached but more input is available */
|
|
if (LINENO(flines[cur_fline]) != target && eof_error > 0) {
|
|
read_lines();
|
|
goto retry;
|
|
}
|
|
}
|
|
else {
|
|
/* search backwards through already-read lines */
|
|
while (LINENO(flines[cur_fline]) != target && cur_fline > 0)
|
|
--cur_fline;
|
|
}
|
|
}
|
|
|
|
static void cap_cur_fline(void)
|
|
{
|
|
if ((option_mask32 & FLAG_S)) {
|
|
if (cur_fline > max_fline)
|
|
cur_fline = max_fline;
|
|
if (LINENO(flines[cur_fline]) + max_displayed_line > max_lineno + TILDES) {
|
|
goto_lineno(max_lineno - max_displayed_line + TILDES);
|
|
read_lines();
|
|
}
|
|
}
|
|
else {
|
|
if (cur_fline + max_displayed_line > max_fline + TILDES)
|
|
cur_fline = max_fline - max_displayed_line + TILDES;
|
|
if (cur_fline < 0)
|
|
cur_fline = 0;
|
|
}
|
|
}
|
|
|
|
/* Move the buffer up and down in the file in order to scroll */
|
|
static void buffer_down(int nlines)
|
|
{
|
|
if ((option_mask32 & FLAG_S))
|
|
goto_lineno(LINENO(flines[cur_fline]) + nlines);
|
|
else
|
|
cur_fline += nlines;
|
|
read_lines();
|
|
cap_cur_fline();
|
|
buffer_fill_and_print();
|
|
}
|
|
|
|
static void buffer_up(int nlines)
|
|
{
|
|
if ((option_mask32 & FLAG_S)) {
|
|
goto_lineno(LINENO(flines[cur_fline]) - nlines);
|
|
}
|
|
else {
|
|
cur_fline -= nlines;
|
|
if (cur_fline < 0)
|
|
cur_fline = 0;
|
|
}
|
|
read_lines();
|
|
buffer_fill_and_print();
|
|
}
|
|
|
|
/* display a given line where the argument can be either an index into
|
|
* the flines array or a line number */
|
|
static void buffer_to_line(int linenum, int is_lineno)
|
|
{
|
|
if (linenum <= 0)
|
|
cur_fline = 0;
|
|
else if (is_lineno)
|
|
goto_lineno(linenum);
|
|
else
|
|
cur_fline = linenum;
|
|
read_lines();
|
|
cap_cur_fline();
|
|
buffer_fill_and_print();
|
|
}
|
|
|
|
static void buffer_line(int linenum)
|
|
{
|
|
buffer_to_line(linenum, FALSE);
|
|
}
|
|
|
|
static void buffer_lineno(int lineno)
|
|
{
|
|
buffer_to_line(lineno, TRUE);
|
|
}
|
|
|
|
static void open_file_and_read_lines(void)
|
|
{
|
|
if (filename) {
|
|
xmove_fd(xopen(filename, O_RDONLY), STDIN_FILENO);
|
|
#if ENABLE_FEATURE_LESS_FLAGS
|
|
num_lines = REOPEN_AND_COUNT;
|
|
#endif
|
|
} else {
|
|
/* "less" with no arguments in argv[] */
|
|
/* For status line only */
|
|
filename = xstrdup(bb_msg_standard_input);
|
|
#if ENABLE_FEATURE_LESS_FLAGS
|
|
num_lines = REOPEN_STDIN;
|
|
#endif
|
|
}
|
|
readpos = 0;
|
|
readeof = 0;
|
|
last_line_pos = 0;
|
|
terminated = 1;
|
|
read_lines();
|
|
}
|
|
|
|
/* Reinitialize everything for a new file - free the memory and start over */
|
|
static void reinitialize(void)
|
|
{
|
|
unsigned i;
|
|
|
|
if (flines) {
|
|
for (i = 0; i <= max_fline; i++)
|
|
free(MEMPTR(flines[i]));
|
|
free(flines);
|
|
flines = NULL;
|
|
}
|
|
|
|
max_fline = -1;
|
|
cur_fline = 0;
|
|
max_lineno = 0;
|
|
open_file_and_read_lines();
|
|
#if ENABLE_FEATURE_LESS_ASK_TERMINAL
|
|
if (G.winsize_err)
|
|
printf("\033[999;999H" "\033[6n");
|
|
#endif
|
|
buffer_fill_and_print();
|
|
}
|
|
|
|
static int64_t getch_nowait(void)
|
|
{
|
|
int rd;
|
|
int64_t key64;
|
|
struct pollfd pfd[2];
|
|
|
|
pfd[0].fd = STDIN_FILENO;
|
|
pfd[0].events = POLLIN;
|
|
pfd[1].fd = kbd_fd;
|
|
pfd[1].events = POLLIN;
|
|
again:
|
|
tcsetattr(kbd_fd, TCSANOW, &term_less);
|
|
/* NB: select/poll returns whenever read will not block. Therefore:
|
|
* if eof is reached, select/poll will return immediately
|
|
* because read will immediately return 0 bytes.
|
|
* Even if select/poll says that input is available, read CAN block
|
|
* (switch fd into O_NONBLOCK'ed mode to avoid it)
|
|
*/
|
|
rd = 1;
|
|
/* Are we interested in stdin? */
|
|
if (at_end()) {
|
|
if (eof_error > 0) /* did NOT reach eof yet */
|
|
rd = 0; /* yes, we are interested in stdin */
|
|
}
|
|
/* Position cursor if line input is done */
|
|
if (less_gets_pos >= 0)
|
|
move_cursor(max_displayed_line + 2, less_gets_pos + 1);
|
|
fflush_all();
|
|
|
|
if (kbd_input[0] == 0) { /* if nothing is buffered */
|
|
#if ENABLE_FEATURE_LESS_WINCH
|
|
while (1) {
|
|
int r;
|
|
/* NB: SIGWINCH interrupts poll() */
|
|
r = poll(pfd + rd, 2 - rd, -1);
|
|
if (/*r < 0 && errno == EINTR &&*/ winch_counter)
|
|
return '\\'; /* anything which has no defined function */
|
|
if (r) break;
|
|
}
|
|
#else
|
|
safe_poll(pfd + rd, 2 - rd, -1);
|
|
#endif
|
|
}
|
|
|
|
/* We have kbd_fd in O_NONBLOCK mode, read inside read_key()
|
|
* would not block even if there is no input available */
|
|
key64 = read_key(kbd_fd, kbd_input, /*timeout off:*/ -2);
|
|
if ((int)key64 == -1) {
|
|
if (errno == EAGAIN) {
|
|
/* No keyboard input available. Since poll() did return,
|
|
* we should have input on stdin */
|
|
read_lines();
|
|
buffer_fill_and_print();
|
|
goto again;
|
|
}
|
|
/* EOF/error (ssh session got killed etc) */
|
|
less_exit(0);
|
|
}
|
|
set_tty_cooked();
|
|
return key64;
|
|
}
|
|
|
|
/* Grab a character from input without requiring the return key.
|
|
* May return KEYCODE_xxx values.
|
|
* Note that this function works best with raw input. */
|
|
static int64_t less_getch(int pos)
|
|
{
|
|
int64_t key64;
|
|
int key;
|
|
|
|
again:
|
|
less_gets_pos = pos;
|
|
key = key64 = getch_nowait();
|
|
less_gets_pos = -1;
|
|
|
|
/* Discard Ctrl-something chars.
|
|
* (checking only lower 32 bits is a size optimization:
|
|
* upper 32 bits are used only by KEYCODE_CURSOR_POS)
|
|
*/
|
|
if (key >= 0 && key < ' ' && key != 0x0d && key != 8)
|
|
goto again;
|
|
|
|
return key64;
|
|
}
|
|
|
|
static char* less_gets(int sz)
|
|
{
|
|
int c;
|
|
unsigned i = 0;
|
|
char *result = xzalloc(1);
|
|
|
|
while (1) {
|
|
c = '\0';
|
|
less_gets_pos = sz + i;
|
|
c = getch_nowait();
|
|
if (c == 0x0d) {
|
|
result[i] = '\0';
|
|
less_gets_pos = -1;
|
|
return result;
|
|
}
|
|
if (c == 0x7f)
|
|
c = 8;
|
|
if (c == 8 && i) {
|
|
printf("\x8 \x8");
|
|
i--;
|
|
}
|
|
if (c < ' ') /* filters out KEYCODE_xxx too (<0) */
|
|
continue;
|
|
if (i >= width - sz - 1)
|
|
continue; /* len limit */
|
|
bb_putchar(c);
|
|
result[i++] = c;
|
|
result = xrealloc(result, i+1);
|
|
}
|
|
}
|
|
|
|
static void examine_file(void)
|
|
{
|
|
char *new_fname;
|
|
|
|
print_statusline("Examine: ");
|
|
new_fname = less_gets(sizeof("Examine: ") - 1);
|
|
if (!new_fname[0]) {
|
|
status_print();
|
|
err:
|
|
free(new_fname);
|
|
return;
|
|
}
|
|
if (access(new_fname, R_OK) != 0) {
|
|
print_statusline("Cannot read this file");
|
|
goto err;
|
|
}
|
|
free(filename);
|
|
filename = new_fname;
|
|
/* files start by = argv. why we assume that argv is infinitely long??
|
|
files[num_files] = filename;
|
|
current_file = num_files + 1;
|
|
num_files++; */
|
|
files[0] = filename;
|
|
num_files = current_file = 1;
|
|
reinitialize();
|
|
}
|
|
|
|
/* This function changes the file currently being paged. direction can be one of the following:
|
|
* -1: go back one file
|
|
* 0: go to the first file
|
|
* 1: go forward one file */
|
|
static void change_file(int direction)
|
|
{
|
|
if (current_file != ((direction > 0) ? num_files : 1)) {
|
|
current_file = direction ? current_file + direction : 1;
|
|
free(filename);
|
|
filename = xstrdup(files[current_file - 1]);
|
|
reinitialize();
|
|
} else {
|
|
print_statusline(direction > 0 ? "No next file" : "No previous file");
|
|
}
|
|
}
|
|
|
|
static void remove_current_file(void)
|
|
{
|
|
unsigned i;
|
|
|
|
if (num_files < 2)
|
|
return;
|
|
|
|
if (current_file != 1) {
|
|
change_file(-1);
|
|
for (i = 3; i <= num_files; i++)
|
|
files[i - 2] = files[i - 1];
|
|
num_files--;
|
|
} else {
|
|
change_file(1);
|
|
for (i = 2; i <= num_files; i++)
|
|
files[i - 2] = files[i - 1];
|
|
num_files--;
|
|
current_file--;
|
|
}
|
|
}
|
|
|
|
static void colon_process(void)
|
|
{
|
|
int keypress;
|
|
|
|
/* Clear the current line and print a prompt */
|
|
print_statusline(" :");
|
|
|
|
keypress = less_getch(2);
|
|
switch (keypress) {
|
|
case 'd':
|
|
remove_current_file();
|
|
break;
|
|
case 'e':
|
|
examine_file();
|
|
break;
|
|
#if ENABLE_FEATURE_LESS_FLAGS
|
|
case 'f':
|
|
m_status_print();
|
|
break;
|
|
#endif
|
|
case 'n':
|
|
change_file(1);
|
|
break;
|
|
case 'p':
|
|
change_file(-1);
|
|
break;
|
|
case 'q':
|
|
less_exit(EXIT_SUCCESS);
|
|
break;
|
|
case 'x':
|
|
change_file(0);
|
|
break;
|
|
}
|
|
}
|
|
|
|
#if ENABLE_FEATURE_LESS_REGEXP
|
|
static void normalize_match_pos(int match)
|
|
{
|
|
if (match >= num_matches)
|
|
match = num_matches - 1;
|
|
if (match < 0)
|
|
match = 0;
|
|
match_pos = match;
|
|
}
|
|
|
|
static void goto_match(int match)
|
|
{
|
|
if (!pattern_valid)
|
|
return;
|
|
if (match < 0)
|
|
match = 0;
|
|
/* Try to find next match if eof isn't reached yet */
|
|
if (match >= num_matches && eof_error > 0) {
|
|
wanted_match = match; /* "I want to read until I see N'th match" */
|
|
read_lines();
|
|
}
|
|
if (num_matches) {
|
|
normalize_match_pos(match);
|
|
buffer_line(match_lines[match_pos]);
|
|
} else {
|
|
print_statusline("No matches found");
|
|
}
|
|
}
|
|
|
|
static void fill_match_lines(unsigned pos)
|
|
{
|
|
if (!pattern_valid)
|
|
return;
|
|
/* Run the regex on each line of the current file */
|
|
while (pos <= max_fline) {
|
|
/* If this line matches */
|
|
if (regexec(&pattern, flines[pos], 0, NULL, 0) == 0
|
|
/* and we didn't match it last time */
|
|
&& !(num_matches && match_lines[num_matches-1] == pos)
|
|
) {
|
|
match_lines = xrealloc_vector(match_lines, 4, num_matches);
|
|
match_lines[num_matches++] = pos;
|
|
}
|
|
pos++;
|
|
}
|
|
}
|
|
|
|
static void regex_process(void)
|
|
{
|
|
char *uncomp_regex, *err;
|
|
|
|
/* Reset variables */
|
|
free(match_lines);
|
|
match_lines = NULL;
|
|
match_pos = 0;
|
|
num_matches = 0;
|
|
if (pattern_valid) {
|
|
regfree(&pattern);
|
|
pattern_valid = 0;
|
|
}
|
|
|
|
/* Get the uncompiled regular expression from the user */
|
|
clear_line();
|
|
bb_putchar((option_mask32 & LESS_STATE_MATCH_BACKWARDS) ? '?' : '/');
|
|
uncomp_regex = less_gets(1);
|
|
if (!uncomp_regex[0]) {
|
|
free(uncomp_regex);
|
|
buffer_print();
|
|
return;
|
|
}
|
|
|
|
/* Compile the regex and check for errors */
|
|
err = regcomp_or_errmsg(&pattern, uncomp_regex,
|
|
(option_mask32 & FLAG_I) ? REG_ICASE : 0);
|
|
free(uncomp_regex);
|
|
if (err) {
|
|
print_statusline(err);
|
|
free(err);
|
|
return;
|
|
}
|
|
|
|
pattern_valid = 1;
|
|
match_pos = 0;
|
|
fill_match_lines(0);
|
|
while (match_pos < num_matches) {
|
|
if ((int)match_lines[match_pos] > cur_fline)
|
|
break;
|
|
match_pos++;
|
|
}
|
|
if (option_mask32 & LESS_STATE_MATCH_BACKWARDS)
|
|
match_pos--;
|
|
|
|
/* It's possible that no matches are found yet.
|
|
* goto_match() will read input looking for match,
|
|
* if needed */
|
|
goto_match(match_pos);
|
|
}
|
|
#endif
|
|
|
|
static void number_process(int first_digit)
|
|
{
|
|
unsigned i;
|
|
int num;
|
|
int keypress;
|
|
char num_input[sizeof(int)*4]; /* more than enough */
|
|
|
|
num_input[0] = first_digit;
|
|
|
|
/* Clear the current line, print a prompt, and then print the digit */
|
|
clear_line();
|
|
printf(":%c", first_digit);
|
|
|
|
/* Receive input until a letter is given */
|
|
i = 1;
|
|
while (i < sizeof(num_input)-1) {
|
|
keypress = less_getch(i + 1);
|
|
if ((unsigned)keypress > 255 || !isdigit(keypress))
|
|
break;
|
|
num_input[i] = keypress;
|
|
bb_putchar(keypress);
|
|
i++;
|
|
}
|
|
|
|
num_input[i] = '\0';
|
|
num = bb_strtou(num_input, NULL, 10);
|
|
/* on format error, num == -1 */
|
|
if (num < 1 || num > MAXLINES) {
|
|
buffer_print();
|
|
return;
|
|
}
|
|
|
|
/* We now know the number and the letter entered, so we process them */
|
|
switch (keypress) {
|
|
case KEYCODE_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015':
|
|
buffer_down(num);
|
|
break;
|
|
case KEYCODE_UP: case 'b': case 'w': case 'y': case 'u':
|
|
buffer_up(num);
|
|
break;
|
|
case 'g': case '<': case 'G': case '>':
|
|
buffer_lineno(num - 1);
|
|
break;
|
|
case 'p': case '%':
|
|
#if ENABLE_FEATURE_LESS_FLAGS
|
|
update_num_lines();
|
|
num = num * (num_lines > 0 ? num_lines : max_lineno) / 100;
|
|
#else
|
|
num = num * max_lineno / 100;
|
|
#endif
|
|
buffer_lineno(num);
|
|
break;
|
|
#if ENABLE_FEATURE_LESS_REGEXP
|
|
case 'n':
|
|
goto_match(match_pos + num);
|
|
break;
|
|
case '/':
|
|
option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
|
|
regex_process();
|
|
break;
|
|
case '?':
|
|
option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
|
|
regex_process();
|
|
break;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
#if ENABLE_FEATURE_LESS_DASHCMD
|
|
static void flag_change(void)
|
|
{
|
|
int keypress;
|
|
|
|
clear_line();
|
|
bb_putchar('-');
|
|
keypress = less_getch(1);
|
|
|
|
switch (keypress) {
|
|
case 'M':
|
|
option_mask32 ^= FLAG_M;
|
|
break;
|
|
case 'm':
|
|
option_mask32 ^= FLAG_m;
|
|
break;
|
|
case 'E':
|
|
option_mask32 ^= FLAG_E;
|
|
break;
|
|
case '~':
|
|
option_mask32 ^= FLAG_TILDE;
|
|
break;
|
|
#if ENABLE_FEATURE_LESS_TRUNCATE
|
|
case 'S':
|
|
option_mask32 ^= FLAG_S;
|
|
buffer_fill_and_print();
|
|
break;
|
|
#endif
|
|
#if ENABLE_FEATURE_LESS_LINENUMS
|
|
case 'N':
|
|
option_mask32 ^= FLAG_N;
|
|
re_wrap();
|
|
buffer_fill_and_print();
|
|
break;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
#ifdef BLOAT
|
|
static void show_flag_status(void)
|
|
{
|
|
int keypress;
|
|
int flag_val;
|
|
|
|
clear_line();
|
|
bb_putchar('_');
|
|
keypress = less_getch(1);
|
|
|
|
switch (keypress) {
|
|
case 'M':
|
|
flag_val = option_mask32 & FLAG_M;
|
|
break;
|
|
case 'm':
|
|
flag_val = option_mask32 & FLAG_m;
|
|
break;
|
|
case '~':
|
|
flag_val = option_mask32 & FLAG_TILDE;
|
|
break;
|
|
case 'N':
|
|
flag_val = option_mask32 & FLAG_N;
|
|
break;
|
|
case 'E':
|
|
flag_val = option_mask32 & FLAG_E;
|
|
break;
|
|
default:
|
|
flag_val = 0;
|
|
break;
|
|
}
|
|
|
|
clear_line();
|
|
printf(HIGHLIGHT"The status of the flag is: %u"NORMAL, flag_val != 0);
|
|
}
|
|
#endif
|
|
|
|
#endif /* ENABLE_FEATURE_LESS_DASHCMD */
|
|
|
|
static void save_input_to_file(void)
|
|
{
|
|
const char *msg = "";
|
|
char *current_line;
|
|
unsigned i;
|
|
FILE *fp;
|
|
|
|
print_statusline("Log file: ");
|
|
current_line = less_gets(sizeof("Log file: ")-1);
|
|
if (current_line[0]) {
|
|
fp = fopen_for_write(current_line);
|
|
if (!fp) {
|
|
msg = "Error opening log file";
|
|
goto ret;
|
|
}
|
|
for (i = 0; i <= max_fline; i++)
|
|
fprintf(fp, "%s\n", flines[i]);
|
|
fclose(fp);
|
|
msg = "Done";
|
|
}
|
|
ret:
|
|
print_statusline(msg);
|
|
free(current_line);
|
|
}
|
|
|
|
#if ENABLE_FEATURE_LESS_MARKS
|
|
static void add_mark(void)
|
|
{
|
|
int letter;
|
|
|
|
print_statusline("Mark: ");
|
|
letter = less_getch(sizeof("Mark: ") - 1);
|
|
|
|
if (isalpha(letter)) {
|
|
/* If we exceed 15 marks, start overwriting previous ones */
|
|
if (num_marks == 14)
|
|
num_marks = 0;
|
|
|
|
mark_lines[num_marks][0] = letter;
|
|
mark_lines[num_marks][1] = cur_fline;
|
|
num_marks++;
|
|
} else {
|
|
print_statusline("Invalid mark letter");
|
|
}
|
|
}
|
|
|
|
static void goto_mark(void)
|
|
{
|
|
int letter;
|
|
int i;
|
|
|
|
print_statusline("Go to mark: ");
|
|
letter = less_getch(sizeof("Go to mark: ") - 1);
|
|
clear_line();
|
|
|
|
if (isalpha(letter)) {
|
|
for (i = 0; i <= num_marks; i++)
|
|
if (letter == mark_lines[i][0]) {
|
|
buffer_line(mark_lines[i][1]);
|
|
break;
|
|
}
|
|
if (num_marks == 14 && letter != mark_lines[14][0])
|
|
print_statusline("Mark not set");
|
|
} else
|
|
print_statusline("Invalid mark letter");
|
|
}
|
|
#endif
|
|
|
|
#if ENABLE_FEATURE_LESS_BRACKETS
|
|
static char opp_bracket(char bracket)
|
|
{
|
|
switch (bracket) {
|
|
case '{': case '[': /* '}' == '{' + 2. Same for '[' */
|
|
bracket++;
|
|
case '(': /* ')' == '(' + 1 */
|
|
bracket++;
|
|
break;
|
|
case '}': case ']':
|
|
bracket--;
|
|
case ')':
|
|
bracket--;
|
|
break;
|
|
};
|
|
return bracket;
|
|
}
|
|
|
|
static void match_right_bracket(char bracket)
|
|
{
|
|
unsigned i = cur_fline;
|
|
|
|
if (i >= max_fline
|
|
|| strchr(flines[i], bracket) == NULL
|
|
) {
|
|
print_statusline("No bracket in top line");
|
|
return;
|
|
}
|
|
|
|
bracket = opp_bracket(bracket);
|
|
for (; i < max_fline; i++) {
|
|
if (strchr(flines[i], bracket) != NULL) {
|
|
/*
|
|
* Line with matched right bracket becomes
|
|
* last visible line
|
|
*/
|
|
buffer_line(i - max_displayed_line);
|
|
return;
|
|
}
|
|
}
|
|
print_statusline("No matching bracket found");
|
|
}
|
|
|
|
static void match_left_bracket(char bracket)
|
|
{
|
|
int i = cur_fline + max_displayed_line;
|
|
|
|
if (i >= max_fline
|
|
|| strchr(flines[i], bracket) == NULL
|
|
) {
|
|
print_statusline("No bracket in bottom line");
|
|
return;
|
|
}
|
|
|
|
bracket = opp_bracket(bracket);
|
|
for (; i >= 0; i--) {
|
|
if (strchr(flines[i], bracket) != NULL) {
|
|
/*
|
|
* Line with matched left bracket becomes
|
|
* first visible line
|
|
*/
|
|
buffer_line(i);
|
|
return;
|
|
}
|
|
}
|
|
print_statusline("No matching bracket found");
|
|
}
|
|
#endif /* FEATURE_LESS_BRACKETS */
|
|
|
|
static void keypress_process(int keypress)
|
|
{
|
|
switch (keypress) {
|
|
case KEYCODE_DOWN: case 'e': case 'j': case 0x0d:
|
|
buffer_down(1);
|
|
break;
|
|
case KEYCODE_UP: case 'y': case 'k':
|
|
buffer_up(1);
|
|
break;
|
|
case KEYCODE_PAGEDOWN: case ' ': case 'z': case 'f':
|
|
buffer_down(max_displayed_line + 1);
|
|
break;
|
|
case KEYCODE_PAGEUP: case 'w': case 'b':
|
|
buffer_up(max_displayed_line + 1);
|
|
break;
|
|
case 'd':
|
|
buffer_down((max_displayed_line + 1) / 2);
|
|
break;
|
|
case 'u':
|
|
buffer_up((max_displayed_line + 1) / 2);
|
|
break;
|
|
case KEYCODE_HOME: case 'g': case 'p': case '<': case '%':
|
|
buffer_line(0);
|
|
break;
|
|
case KEYCODE_END: case 'G': case '>':
|
|
cur_fline = MAXLINES;
|
|
read_lines();
|
|
buffer_line(cur_fline);
|
|
break;
|
|
case 'q': case 'Q':
|
|
less_exit(EXIT_SUCCESS);
|
|
break;
|
|
#if ENABLE_FEATURE_LESS_MARKS
|
|
case 'm':
|
|
add_mark();
|
|
buffer_print();
|
|
break;
|
|
case '\'':
|
|
goto_mark();
|
|
buffer_print();
|
|
break;
|
|
#endif
|
|
case 'r': case 'R':
|
|
/* TODO: (1) also bind ^R, ^L to this?
|
|
* (2) re-measure window size?
|
|
*/
|
|
buffer_print();
|
|
break;
|
|
/*case 'R':
|
|
full_repaint();
|
|
break;*/
|
|
case 's':
|
|
save_input_to_file();
|
|
break;
|
|
case 'E':
|
|
examine_file();
|
|
break;
|
|
#if ENABLE_FEATURE_LESS_FLAGS
|
|
case '=':
|
|
m_status_print();
|
|
break;
|
|
#endif
|
|
#if ENABLE_FEATURE_LESS_REGEXP
|
|
case '/':
|
|
option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
|
|
regex_process();
|
|
break;
|
|
case 'n':
|
|
goto_match(match_pos + 1);
|
|
break;
|
|
case 'N':
|
|
goto_match(match_pos - 1);
|
|
break;
|
|
case '?':
|
|
option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
|
|
regex_process();
|
|
break;
|
|
#endif
|
|
#if ENABLE_FEATURE_LESS_DASHCMD
|
|
case '-':
|
|
flag_change();
|
|
buffer_print();
|
|
break;
|
|
#ifdef BLOAT
|
|
case '_':
|
|
show_flag_status();
|
|
break;
|
|
#endif
|
|
#endif
|
|
#if ENABLE_FEATURE_LESS_BRACKETS
|
|
case '{': case '(': case '[':
|
|
match_right_bracket(keypress);
|
|
break;
|
|
case '}': case ')': case ']':
|
|
match_left_bracket(keypress);
|
|
break;
|
|
#endif
|
|
case ':':
|
|
colon_process();
|
|
break;
|
|
}
|
|
|
|
if (isdigit(keypress))
|
|
number_process(keypress);
|
|
}
|
|
|
|
static void sig_catcher(int sig)
|
|
{
|
|
less_exit(- sig);
|
|
}
|
|
|
|
#if ENABLE_FEATURE_LESS_WINCH
|
|
static void sigwinch_handler(int sig UNUSED_PARAM)
|
|
{
|
|
winch_counter++;
|
|
}
|
|
#endif
|
|
|
|
int less_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
|
int less_main(int argc, char **argv)
|
|
{
|
|
char *tty_name;
|
|
int tty_fd;
|
|
|
|
INIT_G();
|
|
|
|
/* TODO: -x: do not interpret backspace, -xx: tab also
|
|
* -xxx: newline also
|
|
* -w N: assume width N (-xxx -w 32: hex viewer of sorts)
|
|
* -s: condense many empty lines to one
|
|
* (used by some setups for manpage display)
|
|
*/
|
|
getopt32(argv, "EMmN~I" IF_FEATURE_LESS_TRUNCATE("S") /*ignored:*/"s");
|
|
argc -= optind;
|
|
argv += optind;
|
|
num_files = argc;
|
|
files = argv;
|
|
|
|
/* Another popular pager, most, detects when stdout
|
|
* is not a tty and turns into cat. This makes sense. */
|
|
if (!isatty(STDOUT_FILENO))
|
|
return bb_cat(argv);
|
|
|
|
if (!num_files) {
|
|
if (isatty(STDIN_FILENO)) {
|
|
/* Just "less"? No args and no redirection? */
|
|
bb_error_msg("missing filename");
|
|
bb_show_usage();
|
|
}
|
|
} else {
|
|
filename = xstrdup(files[0]);
|
|
}
|
|
|
|
if (option_mask32 & FLAG_TILDE)
|
|
empty_line_marker = "";
|
|
|
|
/* Some versions of less can survive w/o controlling tty,
|
|
* try to do the same. This also allows to specify an alternative
|
|
* tty via "less 1<>TTY".
|
|
*
|
|
* We prefer not to use STDOUT_FILENO directly,
|
|
* since we want to set this fd to non-blocking mode,
|
|
* and not interfere with other processes which share stdout with us.
|
|
*/
|
|
tty_name = xmalloc_ttyname(STDOUT_FILENO);
|
|
if (tty_name) {
|
|
tty_fd = open(tty_name, O_RDONLY);
|
|
free(tty_name);
|
|
if (tty_fd < 0)
|
|
goto try_ctty;
|
|
} else {
|
|
/* Try controlling tty */
|
|
try_ctty:
|
|
tty_fd = open(CURRENT_TTY, O_RDONLY);
|
|
if (tty_fd < 0) {
|
|
/* If all else fails, less 481 uses stdout. Mimic that */
|
|
tty_fd = STDOUT_FILENO;
|
|
}
|
|
}
|
|
G.kbd_fd_orig_flags = ndelay_on(tty_fd);
|
|
kbd_fd = tty_fd; /* save in a global */
|
|
|
|
tcgetattr(kbd_fd, &term_orig);
|
|
term_less = term_orig;
|
|
term_less.c_lflag &= ~(ICANON | ECHO);
|
|
term_less.c_iflag &= ~(IXON | ICRNL);
|
|
/*term_less.c_oflag &= ~ONLCR;*/
|
|
term_less.c_cc[VMIN] = 1;
|
|
term_less.c_cc[VTIME] = 0;
|
|
|
|
IF_FEATURE_LESS_ASK_TERMINAL(G.winsize_err =) get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
|
|
/* 20: two tabstops + 4 */
|
|
if (width < 20 || max_displayed_line < 3)
|
|
return bb_cat(argv);
|
|
max_displayed_line -= 2;
|
|
|
|
/* We want to restore term_orig on exit */
|
|
bb_signals(BB_FATAL_SIGS, sig_catcher);
|
|
#if ENABLE_FEATURE_LESS_WINCH
|
|
signal(SIGWINCH, sigwinch_handler);
|
|
#endif
|
|
|
|
buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
|
|
reinitialize();
|
|
while (1) {
|
|
int64_t keypress;
|
|
|
|
#if ENABLE_FEATURE_LESS_WINCH
|
|
while (WINCH_COUNTER) {
|
|
again:
|
|
winch_counter--;
|
|
IF_FEATURE_LESS_ASK_TERMINAL(G.winsize_err =) get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
|
|
IF_FEATURE_LESS_ASK_TERMINAL(got_size:)
|
|
/* 20: two tabstops + 4 */
|
|
if (width < 20)
|
|
width = 20;
|
|
if (max_displayed_line < 3)
|
|
max_displayed_line = 3;
|
|
max_displayed_line -= 2;
|
|
free(buffer);
|
|
buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
|
|
/* Avoid re-wrap and/or redraw if we already know
|
|
* we need to do it again. These ops are expensive */
|
|
if (WINCH_COUNTER)
|
|
goto again;
|
|
re_wrap();
|
|
if (WINCH_COUNTER)
|
|
goto again;
|
|
buffer_fill_and_print();
|
|
/* This took some time. Loop back and check,
|
|
* were there another SIGWINCH? */
|
|
}
|
|
keypress = less_getch(-1); /* -1: do not position cursor */
|
|
# if ENABLE_FEATURE_LESS_ASK_TERMINAL
|
|
if ((int32_t)keypress == KEYCODE_CURSOR_POS) {
|
|
uint32_t rc = (keypress >> 32);
|
|
width = (rc & 0x7fff);
|
|
max_displayed_line = ((rc >> 16) & 0x7fff);
|
|
goto got_size;
|
|
}
|
|
# endif
|
|
#else
|
|
keypress = less_getch(-1); /* -1: do not position cursor */
|
|
#endif
|
|
keypress_process(keypress);
|
|
}
|
|
}
|
|
|
|
/*
|
|
Help text of less version 418 is below.
|
|
If you are implementing something, keeping
|
|
key and/or command line switch compatibility is a good idea:
|
|
|
|
|
|
SUMMARY OF LESS COMMANDS
|
|
|
|
Commands marked with * may be preceded by a number, N.
|
|
Notes in parentheses indicate the behavior if N is given.
|
|
h H Display this help.
|
|
q :q Q :Q ZZ Exit.
|
|
---------------------------------------------------------------------------
|
|
MOVING
|
|
e ^E j ^N CR * Forward one line (or N lines).
|
|
y ^Y k ^K ^P * Backward one line (or N lines).
|
|
f ^F ^V SPACE * Forward one window (or N lines).
|
|
b ^B ESC-v * Backward one window (or N lines).
|
|
z * Forward one window (and set window to N).
|
|
w * Backward one window (and set window to N).
|
|
ESC-SPACE * Forward one window, but don't stop at end-of-file.
|
|
d ^D * Forward one half-window (and set half-window to N).
|
|
u ^U * Backward one half-window (and set half-window to N).
|
|
ESC-) RightArrow * Left one half screen width (or N positions).
|
|
ESC-( LeftArrow * Right one half screen width (or N positions).
|
|
F Forward forever; like "tail -f".
|
|
r ^R ^L Repaint screen.
|
|
R Repaint screen, discarding buffered input.
|
|
---------------------------------------------------
|
|
Default "window" is the screen height.
|
|
Default "half-window" is half of the screen height.
|
|
---------------------------------------------------------------------------
|
|
SEARCHING
|
|
/pattern * Search forward for (N-th) matching line.
|
|
?pattern * Search backward for (N-th) matching line.
|
|
n * Repeat previous search (for N-th occurrence).
|
|
N * Repeat previous search in reverse direction.
|
|
ESC-n * Repeat previous search, spanning files.
|
|
ESC-N * Repeat previous search, reverse dir. & spanning files.
|
|
ESC-u Undo (toggle) search highlighting.
|
|
---------------------------------------------------
|
|
Search patterns may be modified by one or more of:
|
|
^N or ! Search for NON-matching lines.
|
|
^E or * Search multiple files (pass thru END OF FILE).
|
|
^F or @ Start search at FIRST file (for /) or last file (for ?).
|
|
^K Highlight matches, but don't move (KEEP position).
|
|
^R Don't use REGULAR EXPRESSIONS.
|
|
---------------------------------------------------------------------------
|
|
JUMPING
|
|
g < ESC-< * Go to first line in file (or line N).
|
|
G > ESC-> * Go to last line in file (or line N).
|
|
p % * Go to beginning of file (or N percent into file).
|
|
t * Go to the (N-th) next tag.
|
|
T * Go to the (N-th) previous tag.
|
|
{ ( [ * Find close bracket } ) ].
|
|
} ) ] * Find open bracket { ( [.
|
|
ESC-^F <c1> <c2> * Find close bracket <c2>.
|
|
ESC-^B <c1> <c2> * Find open bracket <c1>
|
|
---------------------------------------------------
|
|
Each "find close bracket" command goes forward to the close bracket
|
|
matching the (N-th) open bracket in the top line.
|
|
Each "find open bracket" command goes backward to the open bracket
|
|
matching the (N-th) close bracket in the bottom line.
|
|
m<letter> Mark the current position with <letter>.
|
|
'<letter> Go to a previously marked position.
|
|
'' Go to the previous position.
|
|
^X^X Same as '.
|
|
---------------------------------------------------
|
|
A mark is any upper-case or lower-case letter.
|
|
Certain marks are predefined:
|
|
^ means beginning of the file
|
|
$ means end of the file
|
|
---------------------------------------------------------------------------
|
|
CHANGING FILES
|
|
:e [file] Examine a new file.
|
|
^X^V Same as :e.
|
|
:n * Examine the (N-th) next file from the command line.
|
|
:p * Examine the (N-th) previous file from the command line.
|
|
:x * Examine the first (or N-th) file from the command line.
|
|
:d Delete the current file from the command line list.
|
|
= ^G :f Print current file name.
|
|
---------------------------------------------------------------------------
|
|
MISCELLANEOUS COMMANDS
|
|
-<flag> Toggle a command line option [see OPTIONS below].
|
|
--<name> Toggle a command line option, by name.
|
|
_<flag> Display the setting of a command line option.
|
|
__<name> Display the setting of an option, by name.
|
|
+cmd Execute the less cmd each time a new file is examined.
|
|
!command Execute the shell command with $SHELL.
|
|
|Xcommand Pipe file between current pos & mark X to shell command.
|
|
v Edit the current file with $VISUAL or $EDITOR.
|
|
V Print version number of "less".
|
|
---------------------------------------------------------------------------
|
|
OPTIONS
|
|
Most options may be changed either on the command line,
|
|
or from within less by using the - or -- command.
|
|
Options may be given in one of two forms: either a single
|
|
character preceded by a -, or a name preceded by --.
|
|
-? ........ --help
|
|
Display help (from command line).
|
|
-a ........ --search-skip-screen
|
|
Forward search skips current screen.
|
|
-b [N] .... --buffers=[N]
|
|
Number of buffers.
|
|
-B ........ --auto-buffers
|
|
Don't automatically allocate buffers for pipes.
|
|
-c ........ --clear-screen
|
|
Repaint by clearing rather than scrolling.
|
|
-d ........ --dumb
|
|
Dumb terminal.
|
|
-D [xn.n] . --color=xn.n
|
|
Set screen colors. (MS-DOS only)
|
|
-e -E .... --quit-at-eof --QUIT-AT-EOF
|
|
Quit at end of file.
|
|
-f ........ --force
|
|
Force open non-regular files.
|
|
-F ........ --quit-if-one-screen
|
|
Quit if entire file fits on first screen.
|
|
-g ........ --hilite-search
|
|
Highlight only last match for searches.
|
|
-G ........ --HILITE-SEARCH
|
|
Don't highlight any matches for searches.
|
|
-h [N] .... --max-back-scroll=[N]
|
|
Backward scroll limit.
|
|
-i ........ --ignore-case
|
|
Ignore case in searches that do not contain uppercase.
|
|
-I ........ --IGNORE-CASE
|
|
Ignore case in all searches.
|
|
-j [N] .... --jump-target=[N]
|
|
Screen position of target lines.
|
|
-J ........ --status-column
|
|
Display a status column at left edge of screen.
|
|
-k [file] . --lesskey-file=[file]
|
|
Use a lesskey file.
|
|
-L ........ --no-lessopen
|
|
Ignore the LESSOPEN environment variable.
|
|
-m -M .... --long-prompt --LONG-PROMPT
|
|
Set prompt style.
|
|
-n -N .... --line-numbers --LINE-NUMBERS
|
|
Don't use line numbers.
|
|
-o [file] . --log-file=[file]
|
|
Copy to log file (standard input only).
|
|
-O [file] . --LOG-FILE=[file]
|
|
Copy to log file (unconditionally overwrite).
|
|
-p [pattern] --pattern=[pattern]
|
|
Start at pattern (from command line).
|
|
-P [prompt] --prompt=[prompt]
|
|
Define new prompt.
|
|
-q -Q .... --quiet --QUIET --silent --SILENT
|
|
Quiet the terminal bell.
|
|
-r -R .... --raw-control-chars --RAW-CONTROL-CHARS
|
|
Output "raw" control characters.
|
|
-s ........ --squeeze-blank-lines
|
|
Squeeze multiple blank lines.
|
|
-S ........ --chop-long-lines
|
|
Chop long lines.
|
|
-t [tag] .. --tag=[tag]
|
|
Find a tag.
|
|
-T [tagsfile] --tag-file=[tagsfile]
|
|
Use an alternate tags file.
|
|
-u -U .... --underline-special --UNDERLINE-SPECIAL
|
|
Change handling of backspaces.
|
|
-V ........ --version
|
|
Display the version number of "less".
|
|
-w ........ --hilite-unread
|
|
Highlight first new line after forward-screen.
|
|
-W ........ --HILITE-UNREAD
|
|
Highlight first new line after any forward movement.
|
|
-x [N[,...]] --tabs=[N[,...]]
|
|
Set tab stops.
|
|
-X ........ --no-init
|
|
Don't use termcap init/deinit strings.
|
|
--no-keypad
|
|
Don't use termcap keypad init/deinit strings.
|
|
-y [N] .... --max-forw-scroll=[N]
|
|
Forward scroll limit.
|
|
-z [N] .... --window=[N]
|
|
Set size of window.
|
|
-" [c[c]] . --quotes=[c[c]]
|
|
Set shell quote characters.
|
|
-~ ........ --tilde
|
|
Don't display tildes after end of file.
|
|
-# [N] .... --shift=[N]
|
|
Horizontal scroll amount (0 = one half screen width)
|
|
|
|
---------------------------------------------------------------------------
|
|
LINE EDITING
|
|
These keys can be used to edit text being entered
|
|
on the "command line" at the bottom of the screen.
|
|
RightArrow ESC-l Move cursor right one character.
|
|
LeftArrow ESC-h Move cursor left one character.
|
|
CNTL-RightArrow ESC-RightArrow ESC-w Move cursor right one word.
|
|
CNTL-LeftArrow ESC-LeftArrow ESC-b Move cursor left one word.
|
|
HOME ESC-0 Move cursor to start of line.
|
|
END ESC-$ Move cursor to end of line.
|
|
BACKSPACE Delete char to left of cursor.
|
|
DELETE ESC-x Delete char under cursor.
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CNTL-BACKSPACE ESC-BACKSPACE Delete word to left of cursor.
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CNTL-DELETE ESC-DELETE ESC-X Delete word under cursor.
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CNTL-U ESC (MS-DOS only) Delete entire line.
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UpArrow ESC-k Retrieve previous command line.
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DownArrow ESC-j Retrieve next command line.
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TAB Complete filename & cycle.
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SHIFT-TAB ESC-TAB Complete filename & reverse cycle.
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CNTL-L Complete filename, list all.
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*/
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