diff options
| -rw-r--r-- | stdlib/getenv.c | 64 |
1 files changed, 5 insertions, 59 deletions
diff --git a/stdlib/getenv.c b/stdlib/getenv.c index e3157ce2f3..8408e641a6 100644 --- a/stdlib/getenv.c +++ b/stdlib/getenv.c @@ -15,76 +15,22 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#include <endian.h> -#include <errno.h> -#include <stdint.h> #include <stdlib.h> #include <string.h> #include <unistd.h> - -/* Return the value of the environment variable NAME. This implementation - is tuned a bit in that it assumes no environment variable has an empty - name which of course should always be true. We have a special case for - one character names so that for the general case we can assume at least - two characters which we can access. By doing this we can avoid using the - `strncmp' most of the time. */ char * getenv (const char *name) { - char **ep; - uint16_t name_start; - if (__environ == NULL || name[0] == '\0') return NULL; - if (name[1] == '\0') - { - /* The name of the variable consists of only one character. Therefore - the first two characters of the environment entry are this character - and a '=' character. */ -#if __BYTE_ORDER == __LITTLE_ENDIAN || !_STRING_ARCH_unaligned - name_start = ('=' << 8) | *(const unsigned char *) name; -#else - name_start = '=' | ((*(const unsigned char *) name) << 8); -#endif - for (ep = __environ; *ep != NULL; ++ep) - { -#if _STRING_ARCH_unaligned - uint16_t ep_start = *(uint16_t *) *ep; -#else - uint16_t ep_start = (((unsigned char *) *ep)[0] - | (((unsigned char *) *ep)[1] << 8)); -#endif - if (name_start == ep_start) - return &(*ep)[2]; - } - } - else + size_t len = strlen (name); + for (char **ep = __environ; *ep != NULL; ++ep) { - size_t len = strlen (name); -#if _STRING_ARCH_unaligned - name_start = *(const uint16_t *) name; -#else - name_start = (((const unsigned char *) name)[0] - | (((const unsigned char *) name)[1] << 8)); -#endif - len -= 2; - name += 2; - - for (ep = __environ; *ep != NULL; ++ep) - { -#if _STRING_ARCH_unaligned - uint16_t ep_start = *(uint16_t *) *ep; -#else - uint16_t ep_start = (((unsigned char *) *ep)[0] - | (((unsigned char *) *ep)[1] << 8)); -#endif - - if (name_start == ep_start && !strncmp (*ep + 2, name, len) - && (*ep)[len + 2] == '=') - return &(*ep)[len + 3]; - } + if (name[0] == (*ep)[0] + && strncmp (name, *ep, len) == 0 && (*ep)[len] == '=') + return *ep + len + 1; } return NULL; |