busybox/coreutils/expand.c
Denis Vlasenko 3139ea7f15 expand: fix incorrect expansion exactly on tab boundary; shrink the code
function                                             old     new   delta
expand_main                                          698     676     -22
xputchar                                              53       -     -53
2008-12-14 15:45:25 +00:00

193 lines
4.3 KiB
C

/* expand - convert tabs to spaces
* unexpand - convert spaces to tabs
*
* Copyright (C) 89, 91, 1995-2006 Free Software Foundation, Inc.
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*
* David MacKenzie <djm@gnu.ai.mit.edu>
*
* Options for expand:
* -t num --tabs=NUM Convert tabs to num spaces (default 8 spaces).
* -i --initial Only convert initial tabs on each line to spaces.
*
* Options for unexpand:
* -a --all Convert all blanks, instead of just initial blanks.
* -f --first-only Convert only leading sequences of blanks (default).
* -t num --tabs=NUM Have tabs num characters apart instead of 8.
*
* Busybox version (C) 2007 by Tito Ragusa <farmatito@tiscali.it>
*
* Caveat: this versions of expand and unexpand don't accept tab lists.
*/
#include "libbb.h"
enum {
OPT_INITIAL = 1 << 0,
OPT_TABS = 1 << 1,
OPT_ALL = 1 << 2,
};
#if ENABLE_EXPAND
static void expand(FILE *file, int tab_size, unsigned opt)
{
char *line;
tab_size = -tab_size;
while ((line = xmalloc_fgets(file)) != NULL) {
int pos;
unsigned char c;
char *ptr = line;
goto start;
while ((c = *ptr) != '\0') {
if ((opt & OPT_INITIAL) && !isblank(c)) {
fputs(ptr, stdout);
break;
}
ptr++;
if (c == '\t') {
c = ' ';
while (++pos < 0)
bb_putchar(c);
}
bb_putchar(c);
if (++pos >= 0) {
start:
pos = tab_size;
}
}
free(line);
}
}
#endif
#if ENABLE_UNEXPAND
static void unexpand(FILE *file, unsigned tab_size, unsigned opt)
{
char *line;
char *ptr;
int convert;
int pos;
int i = 0;
unsigned column = 0;
while ((line = xmalloc_fgets(file)) != NULL) {
convert = 1;
pos = 0;
ptr = line;
while (*line) {
while ((*line == ' ' || *line == '\t') && convert) {
pos += (*line == ' ') ? 1 : tab_size;
line++;
column++;
if ((opt & OPT_ALL) && column == tab_size) {
column = 0;
goto put_tab;
}
}
if (pos) {
i = pos / tab_size;
if (i) {
for (; i > 0; i--) {
put_tab:
bb_putchar('\t');
}
} else {
for (i = pos % tab_size; i > 0; i--) {
bb_putchar(' ');
}
}
pos = 0;
} else {
if (opt & OPT_INITIAL) {
convert = 0;
}
if (opt & OPT_ALL) {
column++;
}
bb_putchar(*line);
line++;
}
}
free(ptr);
}
}
#endif
int expand_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int expand_main(int argc UNUSED_PARAM, char **argv)
{
/* Default 8 spaces for 1 tab */
const char *opt_t = "8";
FILE *file;
unsigned tab_size;
unsigned opt;
int exit_status = EXIT_SUCCESS;
#if ENABLE_FEATURE_EXPAND_LONG_OPTIONS
static const char expand_longopts[] ALIGN1 =
/* name, has_arg, val */
"initial\0" No_argument "i"
"tabs\0" Required_argument "t"
;
#endif
#if ENABLE_FEATURE_UNEXPAND_LONG_OPTIONS
static const char unexpand_longopts[] ALIGN1 =
/* name, has_arg, val */
"first-only\0" No_argument "i"
"tabs\0" Required_argument "t"
"all\0" No_argument "a"
;
#endif
if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e')) {
USE_FEATURE_EXPAND_LONG_OPTIONS(applet_long_options = expand_longopts);
opt = getopt32(argv, "it:", &opt_t);
} else {
USE_FEATURE_UNEXPAND_LONG_OPTIONS(applet_long_options = unexpand_longopts);
/* -t NUM sets also -a */
opt_complementary = "ta";
opt = getopt32(argv, "ft:a", &opt_t);
/* -f --first-only is the default */
if (!(opt & OPT_ALL)) opt |= OPT_INITIAL;
}
tab_size = xatou_range(opt_t, 1, UINT_MAX);
argv += optind;
if (!*argv) {
*--argv = (char*)bb_msg_standard_input;
}
do {
file = fopen_or_warn_stdin(*argv);
if (!file) {
exit_status = EXIT_FAILURE;
continue;
}
if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e'))
USE_EXPAND(expand(file, tab_size, opt));
else
USE_UNEXPAND(unexpand(file, tab_size, opt));
/* Check and close the file */
if (fclose_if_not_stdin(file)) {
bb_simple_perror_msg(*argv);
exit_status = EXIT_FAILURE;
}
/* If stdin also clear EOF */
if (file == stdin)
clearerr(file);
} while (*++argv);
/* Now close stdin also */
/* (if we didn't read from it, it's a no-op) */
if (fclose(stdin))
bb_perror_msg_and_die(bb_msg_standard_input);
fflush_stdout_and_exit(exit_status);
}