/* [<][>][^][v][top][bottom][index][help] */
DEFINITIONS
This source file includes following definitions.
- usage
- adjust_column
- fold_file
- main
/* fold -- wrap each input line to fit in specified width.
Copyright (C) 91, 1995-2006 Free Software Foundation, Inc.
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
/* Written by David MacKenzie, djm@gnu.ai.mit.edu. */
#include <config.h>
#include <stdio.h>
#include <getopt.h>
#include <sys/types.h>
#include "system.h"
#include "error.h"
#include "quote.h"
#include "xstrtol.h"
#define TAB_WIDTH 8
/* The official name of this program (e.g., no `g' prefix). */
#define PROGRAM_NAME "fold"
#define AUTHORS "David MacKenzie"
/* The name this program was run with. */
char *program_name;
/* If nonzero, try to break on whitespace. */
static bool break_spaces;
/* If nonzero, count bytes, not column positions. */
static bool count_bytes;
/* If nonzero, at least one of the files we read was standard input. */
static bool have_read_stdin;
static char const shortopts[] = "bsw:0::1::2::3::4::5::6::7::8::9::";
static struct option const longopts[] =
{
{"bytes", no_argument, NULL, 'b'},
{"spaces", no_argument, NULL, 's'},
{"width", required_argument, NULL, 'w'},
{GETOPT_HELP_OPTION_DECL},
{GETOPT_VERSION_OPTION_DECL},
{NULL, 0, NULL, 0}
};
void
usage (int status)
{
if (status != EXIT_SUCCESS)
fprintf (stderr, _("Try `%s --help' for more information.\n"),
program_name);
else
{
printf (_("\
Usage: %s [OPTION]... [FILE]...\n\
"),
program_name);
fputs (_("\
Wrap input lines in each FILE (standard input by default), writing to\n\
standard output.\n\
\n\
"), stdout);
fputs (_("\
Mandatory arguments to long options are mandatory for short options too.\n\
"), stdout);
fputs (_("\
-b, --bytes count bytes rather than columns\n\
-s, --spaces break at spaces\n\
-w, --width=WIDTH use WIDTH columns instead of 80\n\
"), stdout);
fputs (HELP_OPTION_DESCRIPTION, stdout);
fputs (VERSION_OPTION_DESCRIPTION, stdout);
printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
}
exit (status);
}
/* Assuming the current column is COLUMN, return the column that
printing C will move the cursor to.
The first column is 0. */
static size_t
adjust_column (size_t column, char c)
{
if (!count_bytes)
{
if (c == '\b')
{
if (column > 0)
column--;
}
else if (c == '\r')
column = 0;
else if (c == '\t')
column += TAB_WIDTH - column % TAB_WIDTH;
else /* if (isprint (c)) */
column++;
}
else
column++;
return column;
}
/* Fold file FILENAME, or standard input if FILENAME is "-",
to stdout, with maximum line length WIDTH.
Return true if successful. */
static bool
fold_file (char const *filename, size_t width)
{
FILE *istream;
int c;
size_t column = 0; /* Screen column where next char will go. */
size_t offset_out = 0; /* Index in `line_out' for next char. */
static char *line_out = NULL;
static size_t allocated_out = 0;
int saved_errno;
if (STREQ (filename, "-"))
{
istream = stdin;
have_read_stdin = true;
}
else
istream = fopen (filename, "r");
if (istream == NULL)
{
error (0, errno, "%s", filename);
return false;
}
while ((c = getc (istream)) != EOF)
{
if (offset_out + 1 >= allocated_out)
line_out = X2REALLOC (line_out, &allocated_out);
if (c == '\n')
{
line_out[offset_out++] = c;
fwrite (line_out, sizeof (char), 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)
{
bool found_blank = false;
size_t logical_end = offset_out;
/* Look for the last blank. */
while (logical_end)
{
--logical_end;
if (isblank (to_uchar (line_out[logical_end])))
{
found_blank = true;
break;
}
}
if (found_blank)
{
size_t i;
/* 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;
}
}
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;
}
saved_errno = errno;
if (offset_out)
fwrite (line_out, sizeof (char), (size_t) offset_out, stdout);
if (ferror (istream))
{
error (0, saved_errno, "%s", filename);
if (!STREQ (filename, "-"))
fclose (istream);
return false;
}
if (!STREQ (filename, "-") && fclose (istream) == EOF)
{
error (0, errno, "%s", filename);
return false;
}
return true;
}
int
main (int argc, char **argv)
{
size_t width = 80;
int i;
int optc;
bool ok;
initialize_main (&argc, &argv);
program_name = argv[0];
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
atexit (close_stdout);
break_spaces = count_bytes = have_read_stdin = false;
while ((optc = getopt_long (argc, argv, shortopts, longopts, NULL)) != -1)
{
char optargbuf[2];
switch (optc)
{
case 'b': /* Count bytes rather than columns. */
count_bytes = true;
break;
case 's': /* Break at word boundaries. */
break_spaces = true;
break;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
if (optarg)
optarg--;
else
{
optargbuf[0] = optc;
optargbuf[1] = '\0';
optarg = optargbuf;
}
/* Fall through. */
case 'w': /* Line width. */
{
unsigned long int tmp_ulong;
if (! (xstrtoul (optarg, NULL, 10, &tmp_ulong, "") == LONGINT_OK
&& 0 < tmp_ulong && tmp_ulong < SIZE_MAX - TAB_WIDTH))
error (EXIT_FAILURE, 0,
_("invalid number of columns: %s"), quote (optarg));
width = tmp_ulong;
}
break;
case_GETOPT_HELP_CHAR;
case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
default:
usage (EXIT_FAILURE);
}
}
if (argc == optind)
ok = fold_file ("-", width);
else
{
ok = true;
for (i = optind; i < argc; i++)
ok &= fold_file (argv[i], width);
}
if (have_read_stdin && fclose (stdin) == EOF)
error (EXIT_FAILURE, errno, "-");
exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
}