mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-11-29 02:13:23 +00:00
39 lines
1.0 KiB
C
39 lines
1.0 KiB
C
// makeCWrapper /path/to/executable \
|
|
--prefix PATH : /usr/bin/ \
|
|
--prefix PATH : /usr/local/bin/
|
|
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <assert.h>
|
|
#include <stdio.h>
|
|
|
|
#define assert_success(e) do { if ((e) < 0) { perror(#e); abort(); } } while (0)
|
|
|
|
char *concat3(char *x, char *y, char *z) {
|
|
int xn = strlen(x);
|
|
int yn = strlen(y);
|
|
int zn = strlen(z);
|
|
char *res = malloc(sizeof(*res)*(xn + yn + zn + 1));
|
|
assert(res != NULL);
|
|
strncpy(res, x, xn);
|
|
strncpy(res + xn, y, yn);
|
|
strncpy(res + xn + yn, z, zn);
|
|
res[xn + yn + zn] = '\0';
|
|
return res;
|
|
}
|
|
|
|
void set_env_prefix(char *env, char *sep, char *val) {
|
|
char *existing = getenv(env);
|
|
if (existing) val = concat3(val, sep, existing);
|
|
assert_success(setenv(env, val, 1));
|
|
if (existing) free(val);
|
|
}
|
|
|
|
int main(int argc, char **argv) {
|
|
set_env_prefix("PATH", ":", "/usr/bin/");
|
|
set_env_prefix("PATH", ":", "/usr/local/bin/");
|
|
argv[0] = "/path/to/executable";
|
|
return execv("/path/to/executable", argv);
|
|
}
|