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Diffstat (limited to 'lib/sh/getenv.c')
| -rw-r--r-- | lib/sh/getenv.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/lib/sh/getenv.c b/lib/sh/getenv.c new file mode 100644 index 0000000..8b5e340 --- /dev/null +++ b/lib/sh/getenv.c @@ -0,0 +1,233 @@ +/* getenv.c - get environment variable value from the shell's variable + list. */ + +/* Copyright (C) 1997-2002 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/>. +*/ + +#include <config.h> + +#if defined (CAN_REDEFINE_GETENV) + +#if defined (HAVE_UNISTD_H) +# include <unistd.h> +#endif + +#include <bashansi.h> +#include <errno.h> +#include <shell.h> + +#ifndef errno +extern int errno; +#endif + +extern char **environ; + +/* We supply our own version of getenv () because we want library + routines to get the changed values of exported variables. */ + +/* The NeXT C library has getenv () defined and used in the same file. + This screws our scheme. However, Bash will run on the NeXT using + the C library getenv (), since right now the only environment variable + that we care about is HOME, and that is already defined. */ +static char *last_tempenv_value = (char *)NULL; + +char * +getenv (name) + const char *name; +{ + SHELL_VAR *var; + + if (name == 0 || *name == '\0') + return ((char *)NULL); + + var = find_tempenv_variable ((char *)name); + if (var) + { + FREE (last_tempenv_value); + + last_tempenv_value = value_cell (var) ? savestring (value_cell (var)) : (char *)NULL; + return (last_tempenv_value); + } + else if (shell_variables) + { + var = find_variable ((char *)name); + if (var && exported_p (var)) + return (value_cell (var)); + } + else + { + register int i, len; + + /* In some cases, s5r3 invokes getenv() before main(); BSD systems + using gprof also exhibit this behavior. This means that + shell_variables will be 0 when this is invoked. We look up the + variable in the real environment in that case. */ + + for (i = 0, len = strlen (name); environ[i]; i++) + { + if ((STREQN (environ[i], name, len)) && (environ[i][len] == '=')) + return (environ[i] + len + 1); + } + } + + return ((char *)NULL); +} + +/* Some versions of Unix use _getenv instead. */ +char * +_getenv (name) + const char *name; +{ + return (getenv (name)); +} + +/* SUSv3 says argument is a `char *'; BSD implementations disagree */ +int +putenv (str) +#ifndef HAVE_STD_PUTENV + const char *str; +#else + char *str; +#endif +{ + SHELL_VAR *var; + char *name, *value; + int offset; + + if (str == 0 || *str == '\0') + { + errno = EINVAL; + return -1; + } + + offset = assignment (str, 0); + if (str[offset] != '=') + { + errno = EINVAL; + return -1; + } + name = savestring (str); + name[offset] = 0; + + value = name + offset + 1; + + /* XXX - should we worry about readonly here? */ + var = bind_variable (name, value, 0); + if (var == 0) + { + errno = EINVAL; + return -1; + } + + VUNSETATTR (var, att_invisible); + VSETATTR (var, att_exported); + + return 0; +} + +#if 0 +int +_putenv (name) +#ifndef HAVE_STD_PUTENV + const char *name; +#else + char *name; +#endif +{ + return putenv (name); +} +#endif + +int +setenv (name, value, rewrite) + const char *name; + const char *value; + int rewrite; +{ + SHELL_VAR *var; + char *v; + + if (name == 0 || *name == '\0' || strchr (name, '=') != 0) + { + errno = EINVAL; + return -1; + } + + var = 0; + v = (char *)value; /* some compilers need explicit cast */ + /* XXX - should we worry about readonly here? */ + if (rewrite == 0) + var = find_variable (name); + + if (var == 0) + var = bind_variable (name, v, 0); + + if (var == 0) + return -1; + + VUNSETATTR (var, att_invisible); + VSETATTR (var, att_exported); + + return 0; +} + +#if 0 +int +_setenv (name, value, rewrite) + const char *name; + const char *value; + int rewrite; +{ + return setenv (name, value, rewrite); +} +#endif + +/* SUSv3 says unsetenv returns int; existing implementations (BSD) disagree. */ + +#ifdef HAVE_STD_UNSETENV +#define UNSETENV_RETURN(N) return(N) +#define UNSETENV_RETTYPE int +#else +#define UNSETENV_RETURN(N) return +#define UNSETENV_RETTYPE void +#endif + +UNSETENV_RETTYPE +unsetenv (name) + const char *name; +{ + if (name == 0 || *name == '\0' || strchr (name, '=') != 0) + { + errno = EINVAL; + UNSETENV_RETURN(-1); + } + + /* XXX - should we just remove the export attribute here? */ +#if 1 + unbind_variable (name); +#else + SHELL_VAR *v; + + v = find_variable (name); + if (v) + VUNSETATTR (v, att_exported); +#endif + + UNSETENV_RETURN(0); +} +#endif /* CAN_REDEFINE_GETENV */ |