diff options
| -rw-r--r-- | src/echo.c | 252 |
1 files changed, 137 insertions, 115 deletions
diff --git a/src/echo.c b/src/echo.c index d9ae62032..9467af345 100644 --- a/src/echo.c +++ b/src/echo.c @@ -39,28 +39,16 @@ following backslash-escaped characters is turned on: \t horizontal tab \v vertical tab \\ backslash - \num the character whose ASCII code is NUM (octal). + \0NNN the character whose ASCII code is NNN (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 */ +/* If true, interpret backslash escapes by default. */ +#ifndef DEFAULT_ECHO_TO_XPG +enum { DEFAULT_ECHO_TO_XPG = false }; +#endif /* The name this program was run with. */ char *program_name; @@ -86,9 +74,9 @@ Echo the STRING(s) to standard output.\n\ fputs (VERSION_OPTION_DESCRIPTION, stdout); fputs (_("\ \n\ -Without -E, the following sequences are recognized and interpolated:\n\ +If -e is in effect, the following sequences are recognized:\n\ \n\ - \\NNN the character whose ASCII code is NNN (octal)\n\ + \\0NNN the character whose ASCII code is NNN (octal)\n\ \\\\ backslash\n\ \\a alert (BEL)\n\ \\b backspace\n\ @@ -106,6 +94,22 @@ Without -E, the following sequences are recognized and interpolated:\n\ exit (status); } +/* Convert C from hexadecimal character to integer. */ +static int +hextobin (unsigned char c) +{ + switch (c) + { + default: return c - '0'; + case 'a': case 'A': return 10; + case 'b': case 'B': return 11; + case 'c': case 'C': return 12; + case 'd': case 'D': return 13; + case 'e': case 'E': return 14; + case 'f': case 'F': return 15; + } +} + /* 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. */ @@ -113,8 +117,15 @@ Without -E, the following sequences are recognized and interpolated:\n\ int main (int argc, char **argv) { - int display_return = 1, do_v9 = 0; - int allow_options = 1; + bool display_return = true; + bool allow_options = + (! getenv ("POSIXLY_CORRECT") + || (! DEFAULT_ECHO_TO_XPG && 0 < argc && STREQ (argv[1], "-n"))); + + /* System V machines already have a /bin/sh with a v9 behavior. + Use the identical behavior for these machines so that the + existing system shell scripts won't barf. */ + bool do_v9 = DEFAULT_ECHO_TO_XPG; initialize_main (&argc, &argv); program_name = argv[0]; @@ -124,124 +135,135 @@ main (int argc, char **argv) atexit (close_stdout); - /* Don't recognize --help or --version if POSIXLY_CORRECT is set. */ - if (getenv ("POSIXLY_CORRECT") == NULL) + if (allow_options) parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION, - usage, AUTHORS, (char const *) NULL, NULL); - 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 + usage, AUTHORS, (char const *) NULL); --argc; ++argv; - while (argc > 0 && *argv[0] == '-') - { - register char *temp; - register int i; + if (allow_options) + while (argc > 0 && *argv[0] == '-') + { + char const *temp = argv[0] + 1; + size_t 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; + /* 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. */ - for (i = 0; temp[i]; i++) - { - if (strrchr (VALID_ECHO_OPTIONS, temp[i]) == 0) - goto just_echo; - } + for (i = 0; temp[i]; i++) + switch (temp[i]) + { + case 'e': case 'E': case 'n': + break; + default: + goto just_echo; + } - if (!*temp) - goto just_echo; + if (i == 0) + 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++; - } + /* All of the options in TEMP are valid options to ECHO. + Handle them. */ + while (*temp) + switch (*temp++) + { + case 'e': + do_v9 = true; + break; + + case 'E': + do_v9 = false; + break; + + case 'n': + display_return = false; + break; + } + + argc--; + argv++; + } just_echo: - if (argc > 0) + if (do_v9) { -#if defined (V9_ECHO) - if (do_v9) + while (argc > 0) { - while (argc > 0) - { - register char *s = argv[0]; - register int c; + char const *s = argv[0]; + unsigned char c; - while ((c = *s++)) + while ((c = *s++)) + { + if (c == '\\' && *s) { - if (c == '\\' && *s) + switch (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; - } + case 'a': c = '\a'; break; + case 'b': c = '\b'; break; + case 'c': exit (EXIT_SUCCESS); + case 'f': c = '\f'; break; + case 'n': c = '\n'; break; + case 'r': c = '\r'; break; + case 't': c = '\t'; break; + case 'v': c = '\v'; break; + case 'x': + { + unsigned char ch = *s; + if (! ISXDIGIT (ch)) + goto not_an_escape; + s++; + c = hextobin (ch); + ch = *s; + if (ISXDIGIT (ch)) + { + s++; + c = c * 16 + hextobin (ch); + } + } + break; + case '0': + c = 0; + if (! ('0' <= *s && *s <= '7')) + break; + c = *s++; + /* Fall through. */ + case '1': case '2': case '3': + case '4': case '5': case '6': case '7': + c -= '0'; + if ('0' <= *s && *s <= '7') + c = c * 8 + (*s++ - '0'); + if ('0' <= *s && *s <= '7') + c = c * 8 + (*s++ - '0'); + break; + case '\\': break; + + not_an_escape: + default: putchar ('\\'); break; } - putchar(c); } - argc--; - argv++; - if (argc > 0) - putchar(' '); + putchar (c); } + argc--; + argv++; + if (argc > 0) + putchar (' '); } - else -#endif /* V9_ECHO */ + } + else + { + while (argc > 0) { - while (argc > 0) - { - fputs (argv[0], stdout); - argc--; - argv++; - if (argc > 0) - putchar (' '); - } + fputs (argv[0], stdout); + argc--; + argv++; + if (argc > 0) + putchar (' '); } } + if (display_return) putchar ('\n'); exit (EXIT_SUCCESS); |