| 15 | namespace TinyProcessLib { |
| 16 | |
| 17 | static int portable_execvpe(const char *file, char *const argv[], char *const envp[]) { |
| 18 | #ifdef __GLIBC__ |
| 19 | // Prefer native implementation. |
| 20 | return execvpe(file, argv, envp); |
| 21 | #else |
| 22 | if(!file || !*file) { |
| 23 | errno = ENOENT; |
| 24 | return -1; |
| 25 | } |
| 26 | |
| 27 | if(strchr(file, '/') != nullptr) { |
| 28 | // If file contains a slash, no search is needed. |
| 29 | return execve(file, argv, envp); |
| 30 | } |
| 31 | |
| 32 | const char *path = getenv("PATH"); |
| 33 | char cspath[PATH_MAX + 1] = {}; |
| 34 | if(!path) { |
| 35 | // If env variable is not set, use static path string. |
| 36 | confstr(_CS_PATH, cspath, sizeof(cspath)); |
| 37 | path = cspath; |
| 38 | } |
| 39 | |
| 40 | const size_t path_len = strlen(path); |
| 41 | const size_t file_len = strlen(file); |
| 42 | |
| 43 | if(file_len > NAME_MAX) { |
| 44 | errno = ENAMETOOLONG; |
| 45 | return -1; |
| 46 | } |
| 47 | |
| 48 | // Indicates whether we encountered EACCESS at least once. |
| 49 | bool eacces = false; |
| 50 | |
| 51 | const char *curr = nullptr; |
| 52 | const char *next = nullptr; |
| 53 | |
| 54 | for(curr = path; *curr; curr = *next ? next + 1 : next) { |
| 55 | next = strchr(curr, ':'); |
| 56 | if(!next) { |
| 57 | next = path + path_len; |
| 58 | } |
| 59 | |
| 60 | const size_t sz = (next - curr); |
| 61 | if(sz > PATH_MAX) { |
| 62 | // Path is too long. Proceed to next path in list. |
| 63 | continue; |
| 64 | } |
| 65 | |
| 66 | char exe_path[PATH_MAX + 1 + NAME_MAX + 1]; // 1 byte for slash + 1 byte for \0 |
| 67 | memcpy(exe_path, curr, sz); |
| 68 | exe_path[sz] = '/'; |
| 69 | memcpy(exe_path + sz + 1, file, file_len); |
| 70 | exe_path[sz + 1 + file_len] = '\0'; |
| 71 | |
| 72 | execve(exe_path, argv, envp); |
| 73 | |
| 74 | switch(errno) { |