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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:46:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:46:30 +0000 |
commit | b5896ba9f6047e7031e2bdee0622d543e11a6734 (patch) | |
tree | fd7b460593a2fee1be579bec5697e6d887ea3421 /src/util/environ.c | |
parent | Initial commit. (diff) | |
download | postfix-upstream.tar.xz postfix-upstream.zip |
Adding upstream version 3.4.23.upstream/3.4.23upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/util/environ.c')
-rw-r--r-- | src/util/environ.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/src/util/environ.c b/src/util/environ.c new file mode 100644 index 0000000..4b6c59e --- /dev/null +++ b/src/util/environ.c @@ -0,0 +1,156 @@ + /* + * From: TCP Wrapper. + * + * Many systems have putenv() but no setenv(). Other systems have setenv() but + * no putenv() (MIPS). Still other systems have neither (NeXT). This is a + * re-implementation that hopefully ends all problems. + * + * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. + */ +#include "sys_defs.h" + +#ifdef MISSING_SETENV_PUTENV + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> + +extern char **environ; + +static int addenv(char *); /* append entry to environment */ +static int allocated = 0; /* environ is, or is not, allocated */ + +#define DO_CLOBBER 1 + +/* namelength - determine length of name in "name=whatever" */ + +static ssize_t namelength(const char *name) +{ + char *equal; + + equal = strchr(name, '='); + return ((equal == 0) ? strlen(name) : (equal - name)); +} + +/* findenv - given name, locate name=value */ + +static char **findenv(const char *name, ssize_t len) +{ + char **envp; + + for (envp = environ; envp && *envp; envp++) + if (strncmp(name, *envp, len) == 0 && (*envp)[len] == '=') + return (envp); + return (0); +} + +#if 0 + +/* getenv - given name, locate value */ + +char *getenv(const char *name) +{ + ssize_t len = namelength(name); + char **envp = findenv(name, len); + + return (envp ? *envp + len + 1 : 0); +} + +/* putenv - update or append environment (name,value) pair */ + +int putenv(const char *nameval) +{ + char *equal = strchr(nameval, '='); + char *value = (equal ? equal : ""); + + return (setenv(nameval, value, DO_CLOBBER)); +} + +/* unsetenv - remove variable from environment */ + +void unsetenv(const char *name) +{ + char **envp; + + while ((envp = findenv(name, namelength(name))) != 0) + while (envp[0] = envp[1]) + envp++; +} + +#endif + +/* setenv - update or append environment (name,value) pair */ + +int setenv(const char *name, const char *value, int clobber) +{ + char *destination; + char **envp; + ssize_t l_name; /* length of name part */ + unsigned int l_nameval; /* length of name=value */ + + /* Permit name= and =value. */ + + l_name = namelength(name); + envp = findenv(name, l_name); + if (envp != 0 && clobber == 0) + return (0); + if (*value == '=') + value++; + l_nameval = l_name + strlen(value) + 1; + + /* + * Use available memory if the old value is long enough. Never free an + * old name=value entry because it may not be allocated. + */ + + destination = (envp != 0 && strlen(*envp) >= l_nameval) ? + *envp : malloc(l_nameval + 1); + if (destination == 0) + return (-1); + strncpy(destination, name, l_name); + destination[l_name] = '='; + strcpy(destination + l_name + 1, value); + return ((envp == 0) ? addenv(destination) : (*envp = destination, 0)); +} + +/* cmalloc - malloc and copy block of memory */ + +static char *cmalloc(ssize_t new_len, char *old, ssize_t old_len) +{ + char *new = malloc(new_len); + + if (new != 0) + memcpy(new, old, old_len); + return (new); +} + +/* addenv - append environment entry */ + +static int addenv(char *nameval) +{ + char **envp; + ssize_t n_used; /* number of environment entries */ + ssize_t l_used; /* bytes used excl. terminator */ + ssize_t l_need; /* bytes needed incl. terminator */ + + for (envp = environ; envp && *envp; envp++) + /* void */ ; + n_used = envp - environ; + l_used = n_used * sizeof(*envp); + l_need = l_used + 2 * sizeof(*envp); + + envp = allocated ? + (char **) realloc((char *) environ, l_need) : + (char **) cmalloc(l_need, (char *) environ, l_used); + if (envp == 0) { + return (-1); + } else { + allocated = 1; + environ = envp; + environ[n_used++] = nameval; /* add new entry */ + environ[n_used] = 0; /* terminate list */ + return (0); + } +} + +#endif |