diff options
| -rw-r--r-- | src/librarian.c | 170 |
1 files changed, 164 insertions, 6 deletions
diff --git a/src/librarian.c b/src/librarian.c index e0ed7fe..c33011f 100644 --- a/src/librarian.c +++ b/src/librarian.c @@ -21,10 +21,13 @@ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ +#define _POSIX_C_SOURCE 200809L #include <stdio.h> #include <ctype.h> #include <string.h> #include <stdlib.h> +#include <errno.h> +#include <dirent.h> #include <assert.h> #define t(...) do { if (__VA_ARGS__) goto fail; } while (0) @@ -263,6 +266,155 @@ static int version_cmp(char *a, char *b) /** + * Test whether a version of a library is compatible. + * + * @param version The found version. + * @param required Compatible version range. + * @return 1: Version is accepted. + * 0: Version is incompatible. + */ +static int test_library_version(char *version, struct library *required) +{ + int upper = required->upper ? version_cmp(version, required->upper) : -1; + int lower = required->lower ? version_cmp(version, required->lower) : +1; + + upper = required->lower_closed ? (upper <= 0) : (upper < 0); + lower = required->lower_closed ? (lower >= 0) : (lower > 0); + + return upper && lower; +} + + +/** + * Locate a librarian file in a directory. + * + * @param lib Library specification. + * @param path The pathname of the directory. + * @param oldest Are older versions prefered? + * @return The pathname of the library's librarian file. + * `NULL` on error or if not found, if not found, + * `errno` is set to 0. + */ +static char *locate_in_dir(struct library *lib, char *path, int oldest) +{ + DIR *d = NULL; + struct dirent *f; + char *p; + char *old; + char *best = NULL; + char *best_ver; + int r, saved_errno; + + d = opendir(path); + t (d == NULL); + + while ((f = (errno = 0, readdir(d)))) { + p = strrchr(f->d_name, '='); + if (p == NULL) + continue; + *p = '\0'; + if (strcmp(f->d_name, lib->name)) + continue; + *p++ = '='; + if (!test_library_version(p, lib)) + continue; + if (best == NULL) { + old = best, best = strdup(f->d_name); + } else { + best_ver = strrchr(best, '='); + assert(best_ver && !strchr(best_ver, '/')); + r = version_cmp(p, best_ver + 1); + if (oldest ? (r < 0) : (r > 0)) + old = best, best = strdup(f->d_name); + } + if (best == NULL) { + best = old; + goto fail; + } + free(old); + } + t (errno); + + closedir(d), d = NULL; + + if (best == NULL) + return errno = 0, NULL; + + p = malloc(strlen(path) + strlen(best) + 2); + t (p == NULL); + stpcpy(stpcpy(stpcpy(p, path), "/"), best); + + return p; + +fail: + saved_errno = errno; + free(best); + if (d != NULL) + closedir(d); + errno = saved_errno; + return NULL; +} + + +/** + * Locate a librarian file on the system. + * + * @param lib Library specification. + * @param path LIBRARIAN_PATH. + * @param oldest Are older versions prefered? + * @return The pathname of the library's librarian file. + * `NULL` on error or if not found, if not found, + * `errno` is set to 0. + */ +static char *locate(struct library *lib, char *path, int oldest) +{ + char *p; + char *end = path; + char *e; + char *best = NULL; + char *found; + char *old; + char *best_ver; + char *found_ver; + int r, saved_errno; + + for (p = path; end; *e = (end ? ':' : '\0'), p = end + 1) { + end = strchr(p, ':'); + e = end ? end : strchr(p, '\0'); + *e = '\0'; + if (!*p) + continue; + found = locate_in_dir(lib, p, oldest); + if (found == NULL) { + t (errno); + continue; + } + old = found; + if (best == NULL) { + old = best, best = found; + } else { + best_ver = strrchr(best, '='); + found_ver = strrchr(found, '='); + assert(best_ver && !strchr(best_ver, '/')); + assert(found_ver && !strchr(found_ver, '/')); + r = version_cmp(found_ver + 1, best_ver + 1); + if (oldest ? (r < 0) : (r > 0)) + old = best, best = found; + } + free(old); + } + + return errno = 0, best; + +fail: + saved_errno = errno; + free(best); + errno = saved_errno; + return NULL; +} + + +/** * @return 0: Program was successful. * 1: An error occurred. * 2: A library was not found. @@ -270,8 +422,9 @@ static int version_cmp(char *a, char *b) */ int main(int argc, char *argv[]) { -#define CLEANUP \ - free(libraries) +#define CLEANUP \ + free(libraries), \ + free(path) int dashed = 0, f_deps = 0, f_locate = 0, f_oldest = 0; char *arg; @@ -281,7 +434,8 @@ int main(int argc, char *argv[]) char **variables_last = argv; struct library *libraries = NULL; struct library *libraries_last; - const char *path; + const char *path_; + char *path = NULL; /* Parse arguments. */ argv0 = argv ? (argc--, *argv++) : "pp"; @@ -310,6 +464,8 @@ int main(int argc, char *argv[]) argc--; } } + if (f_deps && f_locate) + goto usage; /* Parse VARIABLE and LIBRARY arguments. */ libraries = malloc((size_t)(args_last - args) * sizeof(*libraries)); @@ -323,9 +479,11 @@ int main(int argc, char *argv[]) } /* Get LIBRARIAN_PATH. */ - path = getenv("LIBRARIAN_PATH"); - if (!path || !*path) - path = DEFAULT_PATH; + path_ = getenv("LIBRARIAN_PATH"); + if (!path_ || !*path_) + path_ = DEFAULT_PATH; + path = strdup(path_); + t (path == NULL); CLEANUP; return 0; |