1 files changed, 135 insertions, 0 deletions
diff --git a/libc/misc/utmp/utent.c b/libc/misc/utmp/utent.c
new file mode 100644
index 000000000..f9d098fb3
--- /dev/null
+++ b/libc/misc/utmp/utent.c
@@ -0,0 +1,135 @@
+/* utent.c <ndf@linux.mit.edu> */
+/* Let it be known that this is very possibly the worst standard ever.  HP-UX
+   does one thing, someone else does another, linux another... If anyone
+   actually has the standard, please send it to me.
+
+   Note that because of the way this stupid stupid standard works, you
+   have to call endutent() to close the file even if you've not called
+   setutent -- getutid and family use the same file descriptor. */
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <paths.h>
+#include <errno.h>
+#include <string.h>
+#include <utmp.h>
+
+static const char *ut_name = _PATH_UTMP;
+
+static int ut_fd = -1;
+
+struct utmp *__getutent(int utmp_fd)
+{
+	static struct utmp utmp;
+	if (read(utmp_fd, (char *) &utmp, sizeof(struct utmp)) !=
+		sizeof(struct utmp)) return NULL;
+
+	return &utmp;
+}
+
+void setutent(void)
+{
+	if (ut_fd != -1)
+		close(ut_fd);
+	if ((ut_fd = open(ut_name, O_RDONLY)) < 0) {
+		perror("setutent: Can't open utmp file");
+		ut_fd = -1;
+	}
+}
+
+void endutent(void)
+{
+	if (ut_fd != -1)
+		close(ut_fd);
+	ut_fd = -1;
+}
+
+struct utmp *getutent(void)
+{
+	if (ut_fd == -1)
+		setutent();
+	if (ut_fd == -1)
+		return NULL;
+	return __getutent(ut_fd);
+}
+
+struct utmp *getutid(struct utmp *utmp_entry)
+{
+	struct utmp *utmp;
+
+	if (ut_fd == -1)
+		setutent();
+	if (ut_fd == -1)
+		return NULL;
+
+	while ((utmp = __getutent(ut_fd)) != NULL) {
+		if ((utmp_entry->ut_type == RUN_LVL ||
+			 utmp_entry->ut_type == BOOT_TIME ||
+			 utmp_entry->ut_type == NEW_TIME ||
+			 utmp_entry->ut_type == OLD_TIME) &&
+			utmp->ut_type == utmp_entry->ut_type) return utmp;
+		if ((utmp_entry->ut_type == INIT_PROCESS ||
+			 utmp_entry->ut_type == DEAD_PROCESS ||
+			 utmp_entry->ut_type == LOGIN_PROCESS ||
+			 utmp_entry->ut_type == USER_PROCESS) &&
+			!strcmp(utmp->ut_id, utmp_entry->ut_id)) return utmp;
+	}
+
+	return NULL;
+}
+
+struct utmp *getutline(struct utmp *utmp_entry)
+{
+	struct utmp *utmp;
+
+	if (ut_fd == -1)
+		setutent();
+	if (ut_fd == -1)
+		return NULL;
+
+#if 0
+	/* This is driving me nuts.  It's not an implementation problem -
+	   it's a matter of how things _SHOULD_ behave.  Groan. */
+	lseek(ut_fd, SEEK_CUR, -sizeof(struct utmp));
+#endif
+
+	while ((utmp = __getutent(ut_fd)) != NULL) {
+		if ((utmp->ut_type == USER_PROCESS ||
+			 utmp->ut_type == LOGIN_PROCESS) &&
+			!strcmp(utmp->ut_line, utmp_entry->ut_line)) return utmp;
+	}
+
+	return NULL;
+}
+
+struct utmp *pututline(struct utmp *utmp_entry)
+{
+	struct utmp *ut;
+
+	/* Ignore the return value.  That way, if they've already positioned
+	   the file pointer where they want it, everything will work out. */
+	(void) lseek(ut_fd, (off_t) - sizeof(utmp_entry), SEEK_CUR);
+
+	if ((ut = getutid(utmp_entry)) != NULL) {
+		lseek(ut_fd, (off_t) - sizeof(utmp_entry), SEEK_CUR);
+		if (write(ut_fd, (char *) utmp_entry, sizeof(utmp_entry))
+			!= sizeof(utmp_entry))
+			return NULL;
+	} else {
+		lseek(ut_fd, (off_t) 0, SEEK_END);
+		if (write(ut_fd, (char *) utmp_entry, sizeof(utmp_entry))
+			!= sizeof(utmp_entry))
+			return NULL;
+	}
+
+	return utmp_entry;
+}
+
+void utmpname(const char *new_ut_name)
+{
+	if (new_ut_name != NULL)
+		ut_name = new_ut_name;
+
+	if (ut_fd != -1)
+		close(ut_fd);
+}