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Diffstat (limited to 'builtins/echo.def')
| -rw-r--r-- | builtins/echo.def | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/builtins/echo.def b/builtins/echo.def new file mode 100644 index 0000000..4e2243d --- /dev/null +++ b/builtins/echo.def @@ -0,0 +1,202 @@ +This file is echo.def, from which is created echo.c. +It implements the builtin "echo" in Bash. + +Copyright (C) 1987-2018 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 3 of the License, 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. If not, see <http://www.gnu.org/licenses/>. + +$PRODUCES echo.c +#include <config.h> + +#if defined (HAVE_UNISTD_H) +# include <unistd.h> +#endif + +#include "../bashansi.h" + +#include <stdio.h> +#include "../shell.h" + +#include "common.h" + +$BUILTIN echo +$FUNCTION echo_builtin +$DEPENDS_ON V9_ECHO +$SHORT_DOC echo [-neE] [arg ...] +Write arguments to the standard output. + +Display the ARGs, separated by a single space character and followed by a +newline, on the standard output. + +Options: + -n do not append a newline + -e enable interpretation of the following backslash escapes + -E explicitly suppress interpretation of backslash escapes + +`echo' interprets the following backslash-escaped characters: + \a alert (bell) + \b backspace + \c suppress further output + \e escape character + \E escape character + \f form feed + \n new line + \r carriage return + \t horizontal tab + \v vertical tab + \\ backslash + \0nnn the character whose ASCII code is NNN (octal). NNN can be + 0 to 3 octal digits + \xHH the eight-bit character whose value is HH (hexadecimal). HH + can be one or two hex digits + \uHHHH the Unicode character whose value is the hexadecimal value HHHH. + HHHH can be one to four hex digits. + \UHHHHHHHH the Unicode character whose value is the hexadecimal value + HHHHHHHH. HHHHHHHH can be one to eight hex digits. + +Exit Status: +Returns success unless a write error occurs. +$END + +$BUILTIN echo +$FUNCTION echo_builtin +$DEPENDS_ON !V9_ECHO +$SHORT_DOC echo [-n] [arg ...] +Write arguments to the standard output. + +Display the ARGs on the standard output followed by a newline. + +Options: + -n do not append a newline + +Exit Status: +Returns success unless a write error occurs. +$END + +#if defined (V9_ECHO) +# define VALID_ECHO_OPTIONS "neE" +#else /* !V9_ECHO */ +# define VALID_ECHO_OPTIONS "n" +#endif /* !V9_ECHO */ + +/* 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. Regrettably, the SUS v2 has + standardized the Sys V echo behavior. This variable is external + so that we can have a `shopt' variable to control it at runtime. */ +#if defined (DEFAULT_ECHO_TO_XPG) || defined (STRICT_POSIX) +int xpg_echo = 1; +#else +int xpg_echo = 0; +#endif /* DEFAULT_ECHO_TO_XPG */ + +/* 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 +echo_builtin (list) + WORD_LIST *list; +{ + int display_return, do_v9, i, len; + char *temp, *s; + + do_v9 = xpg_echo; + display_return = 1; + + if (posixly_correct && xpg_echo) + goto just_echo; + + for (; list && (temp = list->word->word) && *temp == '-'; list = list->next) + { + /* 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++; + + for (i = 0; temp[i]; i++) + { + if (strchr (VALID_ECHO_OPTIONS, temp[i]) == 0) + break; + } + + /* echo - and echo -<nonopt> both mean to just echo the arguments. */ + if (*temp == 0 || temp[i]) + break; + + /* All of the options in TEMP are valid options to ECHO. + Handle them. */ + while (i = *temp++) + { + switch (i) + { + case 'n': + display_return = 0; + break; +#if defined (V9_ECHO) + case 'e': + do_v9 = 1; + break; + case 'E': + do_v9 = 0; + break; +#endif /* V9_ECHO */ + default: + goto just_echo; /* XXX */ + } + } + } + +just_echo: + + clearerr (stdout); /* clear error before writing and testing success */ + + while (list) + { + i = len = 0; + temp = do_v9 ? ansicstr (list->word->word, STRLEN (list->word->word), 1, &i, &len) + : list->word->word; + if (temp) + { + if (do_v9) + { + for (s = temp; len > 0; len--) + putchar (*s++); + } + else + printf ("%s", temp); +#if defined (SunOS5) + fflush (stdout); /* Fix for bug in SunOS 5.5 printf(3) */ +#endif + } + QUIT; + if (do_v9 && temp) + free (temp); + list = list->next; + if (i) + { + display_return = 0; + break; + } + if (list) + putchar(' '); + QUIT; + } + + if (display_return) + putchar ('\n'); + + return (sh_chkwrite (EXECUTION_SUCCESS)); +} |