busybox/coreutils/fold.c
2003-04-27 10:05:35 +00:00

195 lines
4.9 KiB
C

/* fold -- wrap each input line to fit in specified width.
Written by David MacKenzie, djm@gnu.ai.mit.edu.
Copyright (C) 91, 1995-2002 Free Software Foundation, Inc.
Modified for busybox based on coreutils v 5.0
Copyright (C) 2003 Glenn McGrath <bug1@optushome.com.au>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include <sys/types.h>
#include "busybox.h"
/* If nonzero, count bytes, not column positions. */
static int count_bytes;
/* Assuming the current column is COLUMN, return the column that
printing C will move the cursor to.
The first column is 0. */
static int adjust_column(int column, char c)
{
if (!count_bytes) {
if (c == '\b') {
if (column > 0)
column--;
} else if (c == '\r')
column = 0;
else if (c == '\t')
column = column + 8 - column % 8;
else /* if (isprint (c)) */
column++;
} else
column++;
return column;
}
extern int fold_main(int argc, char **argv)
{
/* If nonzero, try to break on whitespace. */
int break_spaces;
/* If nonzero, at least one of the files we read was standard input. */
int have_read_stdin;
int width = 80;
int i;
int optc;
int errs = 0;
break_spaces = count_bytes = have_read_stdin = 0;
/* Turn any numeric options into -w options. */
for (i = 1; i < argc; i++) {
char const *a = argv[i];
if (a[0] == '-') {
if (a[1] == '-' && !a[2])
break;
if (isdigit(a[1])) {
char *s = xmalloc(strlen(a) + 2);
s[0] = '-';
s[1] = 'w';
strcpy(s + 2, a + 1);
argv[i] = s;
}
}
}
while ((optc = getopt(argc, argv, "bsw:")) > 0) {
switch (optc) {
case 'b': /* Count bytes rather than columns. */
count_bytes = 1;
break;
case 's': /* Break at word boundaries. */
break_spaces = 1;
break;
case 'w': { /* Line width. */
width = bb_xgetlarg(optarg, 10, 1, 10000);
break;
}
default:
bb_show_usage();
}
}
argv += optind;
if (!*argv) {
*--argv = "-";
}
do {
FILE *istream = bb_wfopen_input(*argv);
if (istream != NULL) {
int c;
int column = 0; /* Screen column where next char will go. */
int offset_out = 0; /* Index in `line_out' for next char. */
static char *line_out = NULL;
static int allocated_out = 0;
while ((c = getc(istream)) != EOF) {
if (offset_out + 1 >= allocated_out) {
allocated_out += 1024;
line_out = xrealloc(line_out, allocated_out);
}
if (c == '\n') {
line_out[offset_out++] = c;
fwrite(line_out, sizeof(char), (size_t) offset_out, stdout);
column = offset_out = 0;
continue;
}
rescan:
column = adjust_column(column, c);
if (column > width) {
/* This character would make the line too long.
Print the line plus a newline, and make this character
start the next line. */
if (break_spaces) {
/* Look for the last blank. */
int logical_end;
for (logical_end = offset_out - 1; logical_end >= 0; logical_end--) {
if (isblank(line_out[logical_end])) {
break;
}
}
if (logical_end >= 0) {
/* Found a blank. Don't output the part after it. */
logical_end++;
fwrite(line_out, sizeof(char), (size_t) logical_end, stdout);
putchar('\n');
/* Move the remainder to the beginning of the next line.
The areas being copied here might overlap. */
memmove(line_out, line_out + logical_end, offset_out - logical_end);
offset_out -= logical_end;
for (column = i = 0; i < offset_out; i++) {
column = adjust_column(column, line_out[i]);
}
goto rescan;
}
} else {
if (offset_out == 0) {
line_out[offset_out++] = c;
continue;
}
}
line_out[offset_out++] = '\n';
fwrite(line_out, sizeof(char), (size_t) offset_out, stdout);
column = offset_out = 0;
goto rescan;
}
line_out[offset_out++] = c;
}
if (offset_out) {
fwrite(line_out, sizeof(char), (size_t) offset_out, stdout);
}
if (ferror(istream) || bb_fclose_nonstdin(istream)) {
bb_perror_msg("%s", *argv); /* Avoid multibyte problems. */
errs |= EXIT_FAILURE;
}
} else {
errs |= EXIT_FAILURE;
}
} while (*++argv);
bb_fflush_stdout_and_exit(errs);
}