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Diffstat (limited to 'builtins/echo.def')
| -rw-r--r-- | builtins/echo.def | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/builtins/echo.def b/builtins/echo.def new file mode 100644 index 0000000..7539103 --- /dev/null +++ b/builtins/echo.def @@ -0,0 +1,168 @@ +This file is echo.def, from which is created echo.c. +It implements the builtin "echo" in Bash. + +Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc. + +This file is part of GNU Bash, the Bourne Again SHell. + +Bash 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 1, or (at your option) any later +version. + +Bash 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 Bash; see the file COPYING. If not, write to the Free Software +Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + +$PRODUCES echo.c +#include <stdio.h> +#include "../shell.h" + +$BUILTIN echo +$FUNCTION echo_builtin +$DEPENDS_ON V9_ECHO +$SHORT_DOC echo [-neE] [arg ...] +Output the ARGs. If -n is specified, the trailing newline is +suppressed. If the -e option is given, interpretation of the +following backslash-escaped characters is turned on: + \a alert (bell) + \b backspace + \c suppress trailing newline + \f form feed + \n new line + \r carriage return + \t horizontal tab + \v vertical tab + \\ backslash + \num the character whose ASCII code is NUM (octal). + +You can explicitly turn off the interpretation of the above characters +with the -E option. +$END + +$BUILTIN echo +$FUNCTION echo_builtin +$DEPENDS_ON !V9_ECHO +$SHORT_DOC echo [-n] [arg ...] +Output the ARGs. If -n is specified, the trailing newline is suppressed. +$END + +#if defined (V9_ECHO) +# define VALID_ECHO_OPTIONS "neE" +#else /* !V9_ECHO */ +# define VALID_ECHO_OPTIONS "n" +#endif /* !V9_ECHO */ + +/* 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. */ +echo_builtin (list) + WORD_LIST *list; +{ + int display_return = 1, do_v9 = 0; + +#if defined (DEFAULT_ECHO_TO_USG) +/* System V machines already have a /bin/sh with a v9 behaviour. We + give Bash the identical behaviour for these machines so that the + existing system shells won't barf. */ + do_v9 = 1; +#endif /* DEFAULT_ECHO_TO_USG */ + + while (list && list->word->word[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 = &(list->word->word[1]); + + for (i = 0; temp[i]; i++) + { + if (strchr (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 (*temp == 'n') + display_return = 0; +#if defined (V9_ECHO) + else if (*temp == 'e') + do_v9 = 1; + else if (*temp == 'E') + do_v9 = 0; +#endif /* V9_ECHO */ + else + goto just_echo; + + temp++; + } + list = list->next; + } + +just_echo: + + if (list) + { +#if defined (V9_ECHO) + if (do_v9) + { + while (list) + { + register char *s = list->word->word; + 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); + } + list = list->next; + if (list) + putchar(' '); + } + } + else +#endif /* V9_ECHO */ + print_word_list (list, " "); + } + if (display_return) + printf ("\n"); + fflush (stdout); + return (EXECUTION_SUCCESS); +} |