1 files changed, 58 insertions, 0 deletions
diff --git a/reference/C/CONTRIB/OR_USING_C/06.1.c b/reference/C/CONTRIB/OR_USING_C/06.1.c
new file mode 100644
index 0000000..2efc718
--- /dev/null
+++ b/reference/C/CONTRIB/OR_USING_C/06.1.c
@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <utmp.h>
+#include <pwd.h>
+
+#define UTMP    "/etc/utmp"
+#define NAMELEN	8
+
+main()
+{
+    FILE *fp;
+    struct utmp u;
+    struct passwd *p;
+    char tmp[NAMELEN+1];
+    struct passwd *getpwnam();
+
+    if ((fp = fopen(UTMP, "r")) == NULL) {
+        perror(UTMP);
+        exit(1);
+    }
+
+    /*
+     * For each entry...
+     */
+    while (fread(&u, sizeof(u), 1, fp) != NULL) {
+        /*
+         * Skip non-logged in ports.
+         */
+        if (u.ut_name[0] == NULL)
+            continue;
+
+        /*
+         * Make sure name is null-terminated.
+         */
+        strncpy(tmp, u.ut_name, NAMELEN);
+
+        /*
+         * Skip non-existent users (shouldn't
+         * be any).
+         */
+        if ((p = getpwnam(tmp)) == NULL)
+            continue;
+
+        /*
+         * Print the line.  ctime() converts the time
+         * to ASCII format, it is described in Chapter
+         * 7, Telling Time and Timing Things. We
+         * ignore the format of the gecos field and
+         * just print the first 30 characters; in real
+         * life we would stop at a comma or some such.
+         */
+        printf("%-10.8s %-10.8s %-30.30s %s", u.ut_name,
+	    u.ut_line, p->pw_gecos, ctime(&u.ut_time));
+    }
+
+    fclose(fp);
+    exit(0);
+}
+