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/* echo.c, derived from code echo.c in Bash.
Copyright (C) 87,89, 1991-1997, 1999-2002 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include <config.h>
#include <stdio.h>
#include <sys/types.h>
#include "system.h"
#include "long-options.h"
/* The official name of this program (e.g., no `g' prefix). */
#define PROGRAM_NAME "echo"
#define WRITTEN_BY _("Written by FIXME unknown.")
/* echo [-neE] [arg ...]
Output the ARGs. If -n is specified, the trailing newline is
suppressed. If the -e option is given, interpretation of the
following backslash-escaped characters is turned on:
\a alert (bell)
\b backspace
\c suppress trailing newline
\f form feed
\n new line
\r carriage return
\t horizontal tab
\v vertical tab
\\ backslash
\num the character whose ASCII code is NUM (octal).
You can explicitly turn off the interpretation of the above characters
on System V systems with the -E option.
*/
/* If defined, interpret backslash escapes if -e is given. */
#define V9_ECHO
/* If defined, interpret backslash escapes unless -E is given.
V9_ECHO must also be defined. */
/* #define V9_DEFAULT */
#if defined (V9_ECHO)
# if defined (V9_DEFAULT)
# define VALID_ECHO_OPTIONS "neE"
# else
# define VALID_ECHO_OPTIONS "ne"
# endif /* !V9_DEFAULT */
#else /* !V9_ECHO */
# define VALID_ECHO_OPTIONS "n"
#endif /* !V9_ECHO */
/* The name this program was run with. */
char *program_name;
void
usage (int status)
{
if (status != 0)
fprintf (stderr, _("Try `%s --help' for more information.\n"),
program_name);
else
{
printf (_("Usage: %s [OPTION]... [STRING]...\n"), program_name);
fputs (_("\
Echo the STRING(s) to standard output.\n\
\n\
-n do not output the trailing newline\n\
-e enable interpretation of the backslash-escaped characters\n\
listed below\n\
-E disable interpretation of those sequences in STRINGs\n\
"), stdout);
fputs (HELP_OPTION_DESCRIPTION, stdout);
fputs (VERSION_OPTION_DESCRIPTION, stdout);
fputs (_("\
\n\
Without -E, the following sequences are recognized and interpolated:\n\
\n\
\\NNN the character whose ASCII code is NNN (octal)\n\
\\\\ backslash\n\
\\a alert (BEL)\n\
\\b backspace\n\
"), stdout);
fputs (_("\
\\c suppress trailing newline\n\
\\f form feed\n\
\\n new line\n\
\\r carriage return\n\
\\t horizontal tab\n\
\\v vertical tab\n\
"), stdout);
printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
}
exit (status);
}
/* Print the words in LIST to standard output. If the first word is
`-n', then don't print a trailing newline. We also support the
echo syntax from Version 9 unix systems. */
int
main (int argc, char **argv)
{
int display_return = 1, do_v9 = 0;
int allow_options = 1;
initialize_main (&argc, &argv);
program_name = argv[0];
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
atexit (close_stdout);
/* Don't recognize --help or --version if POSIXLY_CORRECT is set. */
if (getenv ("POSIXLY_CORRECT") == NULL)
parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
WRITTEN_BY, usage);
else
allow_options = 0;
/* System V machines already have a /bin/sh with a v9 behaviour. We
use the identical behaviour for these machines so that the
existing system shell scripts won't barf. */
#if defined (V9_ECHO) && defined (V9_DEFAULT)
do_v9 = allow_options;
#endif
--argc;
++argv;
while (argc > 0 && *argv[0] == '-')
{
register char *temp;
register int i;
/* If it appears that we are handling options, then make sure that
all of the options specified are actually valid. Otherwise, the
string should just be echoed. */
temp = argv[0] + 1;
for (i = 0; temp[i]; i++)
{
if (strrchr (VALID_ECHO_OPTIONS, temp[i]) == 0)
goto just_echo;
}
if (!*temp)
goto just_echo;
/* All of the options in TEMP are valid options to ECHO.
Handle them. */
while (*temp)
{
if (allow_options && *temp == 'n')
display_return = 0;
#if defined (V9_ECHO)
else if (allow_options && *temp == 'e')
do_v9 = 1;
# if defined (V9_DEFAULT)
else if (allow_options && *temp == 'E')
do_v9 = 0;
# endif /* V9_DEFAULT */
#endif /* V9_ECHO */
else
goto just_echo;
temp++;
}
argc--;
argv++;
}
just_echo:
if (argc > 0)
{
#if defined (V9_ECHO)
if (do_v9)
{
while (argc > 0)
{
register char *s = argv[0];
register int c;
while ((c = *s++))
{
if (c == '\\' && *s)
{
switch (c = *s++)
{
case 'a': c = '\007'; break;
case 'b': c = '\b'; break;
case 'c': display_return = 0; continue;
case 'f': c = '\f'; break;
case 'n': c = '\n'; break;
case 'r': c = '\r'; break;
case 't': c = '\t'; break;
case 'v': c = (int) 0x0B; break;
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
c -= '0';
if (*s >= '0' && *s <= '7')
c = c * 8 + (*s++ - '0');
if (*s >= '0' && *s <= '7')
c = c * 8 + (*s++ - '0');
break;
case '\\': break;
default: putchar ('\\'); break;
}
}
putchar(c);
}
argc--;
argv++;
if (argc > 0)
putchar(' ');
}
}
else
#endif /* V9_ECHO */
{
while (argc > 0)
{
fputs (argv[0], stdout);
argc--;
argv++;
if (argc > 0)
putchar (' ');
}
}
}
if (display_return)
putchar ('\n');
exit (EXIT_SUCCESS);
}
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