pkgs/test/make-binary-wrapper/combination.c

   1 #define _GNU_SOURCE         /* See feature_test_macros(7) */
   2 #include <unistd.h>
   3 #include <stdlib.h>
   4 #include <assert.h>
   5 #include <stdio.h>
   6
   7 #define assert_success(e) do { if ((e) < 0) { perror(#e); abort(); } } while (0)
   8
   9 void set_env_prefix(char *env, char *sep, char *prefix) {
  10     char *existing = getenv(env);
  11     if (existing) {
  12         char *val;
  13         assert_success(asprintf(&val, "%s%s%s", prefix, sep, existing));
  14         assert_success(setenv(env, val, 1));
  15         free(val);
  16     } else {
  17         assert_success(setenv(env, prefix, 1));
  18     }
  19 }
  20
  21 void set_env_suffix(char *env, char *sep, char *suffix) {
  22     char *existing = getenv(env);
  23     if (existing) {
  24         char *val;
  25         assert_success(asprintf(&val, "%s%s%s", existing, sep, suffix));
  26         assert_success(setenv(env, val, 1));
  27         free(val);
  28     } else {
  29         assert_success(setenv(env, suffix, 1));
  30     }
  31 }
  32
  33 int main(int argc, char **argv) {
  34     assert_success(setenv("MESSAGE", "HELLO", 0));
  35     set_env_prefix("PATH", ":", "/usr/bin/");
  36     set_env_suffix("PATH", ":", "/usr/local/bin/");
  37     putenv("MESSAGE2=WORLD");
  38
  39     char **argv_tmp = calloc(3 + argc + 0 + 1, sizeof(*argv_tmp));
  40     assert(argv_tmp != NULL);
  41     argv_tmp[0] = argv[0];
  42     argv_tmp[1] = "-x";
  43     argv_tmp[2] = "-y";
  44     argv_tmp[3] = "-z";
  45     for (int i = 1; i < argc; ++i) {
  46         argv_tmp[3 + i] = argv[i];
  47     }
  48     argv_tmp[3 + argc + 0] = NULL;
  49     argv = argv_tmp;
  50
  51     argv[0] = "my-wrapper";
  52     return execv("/send/me/flags", argv);
  53 }