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-rw-r--r--src/librarian.c170
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;