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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 02:42:50 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 02:42:50 +0000
commit8cb83eee5a58b1fad74c34094ce3afb9e430b5a4 (patch)
treea9b2e7baeca1be40eb734371e3c8b11b02294497 /lib/pwdutils.c
parentInitial commit. (diff)
downloadutil-linux-8cb83eee5a58b1fad74c34094ce3afb9e430b5a4.tar.xz
util-linux-8cb83eee5a58b1fad74c34094ce3afb9e430b5a4.zip
Adding upstream version 2.33.1.upstream/2.33.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--lib/pwdutils.c96
1 files changed, 96 insertions, 0 deletions
diff --git a/lib/pwdutils.c b/lib/pwdutils.c
new file mode 100644
index 0000000..25b4dae
--- /dev/null
+++ b/lib/pwdutils.c
@@ -0,0 +1,96 @@
+#include <stdlib.h>
+
+#include "c.h"
+#include "pwdutils.h"
+#include "xalloc.h"
+
+/* Returns allocated passwd and allocated pwdbuf to store passwd strings
+ * fields. In case of error returns NULL and set errno, for unknown user set
+ * errno to EINVAL
+ */
+struct passwd *xgetpwnam(const char *username, char **pwdbuf)
+{
+ struct passwd *pwd = NULL, *res = NULL;
+ int rc;
+
+ if (!pwdbuf || !username)
+ return NULL;
+
+ *pwdbuf = xmalloc(UL_GETPW_BUFSIZ);
+ pwd = xcalloc(1, sizeof(struct passwd));
+
+ errno = 0;
+ rc = getpwnam_r(username, pwd, *pwdbuf, UL_GETPW_BUFSIZ, &res);
+ if (rc != 0) {
+ errno = rc;
+ goto failed;
+ }
+ if (!res) {
+ errno = EINVAL;
+ goto failed;
+ }
+ return pwd;
+failed:
+ free(pwd);
+ free(*pwdbuf);
+ return NULL;
+}
+
+char *xgetlogin(void)
+{
+ struct passwd *pw = NULL;
+ uid_t ruid;
+ char *user;
+
+ user = getlogin();
+ if (user)
+ return xstrdup(user);
+
+ /* GNU Hurd implementation has an extension where a process can exist in a
+ * non-conforming environment, and thus be outside the realms of POSIX
+ * process identifiers; on this platform, getuid() fails with a status of
+ * (uid_t)(-1) and sets errno if a program is run from a non-conforming
+ * environment.
+ *
+ * http://austingroupbugs.net/view.php?id=511
+ */
+ errno = 0;
+ ruid = getuid();
+
+ if (errno == 0)
+ pw = getpwuid(ruid);
+ if (pw && pw->pw_name && *pw->pw_name)
+ return xstrdup(pw->pw_name);
+
+ return NULL;
+}
+
+#ifdef TEST_PROGRAM
+int main(int argc, char *argv[])
+{
+ char *buf = NULL;
+ struct passwd *pwd = NULL;
+
+ if (argc != 2) {
+ fprintf(stderr, "usage: %s <username>\n", argv[0]);
+ return EXIT_FAILURE;
+ }
+
+ pwd = xgetpwnam(argv[1], &buf);
+ if (!pwd)
+ err(EXIT_FAILURE, "failed to get %s pwd entry", argv[1]);
+
+ printf("Username: %s\n", pwd->pw_name);
+ printf("UID: %d\n", pwd->pw_uid);
+ printf("HOME: %s\n", pwd->pw_dir);
+ printf("GECO: %s\n", pwd->pw_gecos);
+
+ free(pwd);
+ free(buf);
+
+ printf("Current: %s\n", (buf = xgetlogin()));
+ free(buf);
+
+ return EXIT_SUCCESS;
+}
+#endif /* TEST_PROGRAM */