1#include <stdlib.h> 2#include <string.h> 3#include <errno.h> 4 5void __env_rm_add(char *old, char *new) 6{ 7 static char **env_alloced; 8 static size_t env_alloced_n; 9 for (size_t i=0; i < env_alloced_n; i++) 10 if (env_alloced[i] == old) { 11 env_alloced[i] = new; 12 free(old); 13 return; 14 } else if (!env_alloced[i] && new) { 15 env_alloced[i] = new; 16 new = 0; 17 } 18 if (!new) return; 19 char **t = realloc(env_alloced, sizeof *t * (env_alloced_n+1)); 20 if (!t) return; 21 (env_alloced = t)[env_alloced_n++] = new; 22} 23 24int setenv(const char *var, const char *value, int overwrite) 25{ 26 char *s; 27 size_t l1, l2; 28 29 if (!var || !(l1 = __strchrnul(var, '=') - var) || var[l1]) { 30 errno = EINVAL; 31 return -1; 32 } 33 if (!overwrite && getenv(var)) return 0; 34 35 l2 = strlen(value); 36 s = malloc(l1+l2+2); 37 if (!s) return -1; 38 memcpy(s, var, l1); 39 s[l1] = '='; 40 memcpy(s+l1+1, value, l2+1); 41 return __putenv(s, l1, s); 42} 43