summaryrefslogtreecommitdiffstats
path: root/lib/sh/getenv.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--lib/sh/getenv.c233
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..1e682ae
--- /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 if (environ)
+ {
+ 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 */