who: fix attempts to open '/dev/dev/ttyX'; make columns a bit wider, add -H

function                                             old     new   delta
who_main                                             292     363     +71

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

coreutils/who.c

@@ -42,35 +42,47 @@ static void idle_string(char *str6, time_t t)
 int who_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int who_main(int argc UNUSED_PARAM, char **argv)
 {
-	char str6[6];
 	struct utmp *ut;
-	struct stat st;
-	char *name;
 	unsigned opt;
 
 	opt_complementary = "=0";
-	opt = getopt32(argv, "a");
+	opt = getopt32(argv, "aH");
+	if (opt & 2) // -H
+		printf("USER\t\tTTY\t\tIDLE\tTIME\t\t HOST\n");
 
 	setutent();
-	printf("USER       TTY      IDLE      TIME            HOST\n");
 	while ((ut = getutent()) != NULL) {
-		if (ut->ut_user[0] && (opt || ut->ut_type == USER_PROCESS)) {
+		if (ut->ut_user[0]
-			time_t tmp;
+		 && ((opt & 1) || ut->ut_type == USER_PROCESS)
-			/* ut->ut_line is device name of tty - "/dev/" */
+		) {
-			name = concat_path_file("/dev", ut->ut_line);
+			char str6[6];
+			char name[sizeof("/dev/") + sizeof(ut->ut_line) + 1];
+			struct stat st;
+			time_t seconds;
+
 			str6[0] = '?';
 			str6[1] = '\0';
+			strcpy(name, "/dev/");
+			safe_strncpy(ut->ut_line[0] == '/' ? name : name + sizeof("/dev/")-1,
+				ut->ut_line,
+				sizeof(ut->ut_line)+1
+			);
 			if (stat(name, &st) == 0)
 				idle_string(str6, st.st_atime);
 			/* manpages say ut_tv.tv_sec *is* time_t,
 			 * but some systems have it wrong */
-			tmp = ut->ut_tv.tv_sec;
+			seconds = ut->ut_tv.tv_sec;
-			/* 15 chars for time:   Nov 10 19:33:20 */
+			/* How wide time field can be?
-			printf("%-10s %-8s %-9s %-15.15s %s\n",
+			 * "Nov 10 19:33:20": 15 chars
-					ut->ut_user, ut->ut_line, str6,
+			 * "2010-11-10 19:33": 16 chars
-					ctime(&tmp) + 4, ut->ut_host);
+			 */
-			if (ENABLE_FEATURE_CLEAN_UP)
+			printf("%-15.*s %-15.*s %-7s %-16.16s %.*s\n",
-				free(name);
+					(int)sizeof(ut->ut_user), ut->ut_user,
+					(int)sizeof(ut->ut_line), ut->ut_line,
+					str6,
+					ctime(&seconds) + 4,
+					(int)sizeof(ut->ut_host), ut->ut_host
+			);
 		}
 	}
 	if (ENABLE_FEATURE_CLEAN_UP)

loginutils/login.c

@@ -61,7 +61,7 @@ static void read_or_build_utent(struct utmp *utptr, int run_by_root)
 
 	/* First, try to find a valid utmp entry for this process.  */
 	/* If there is one, just use it.  */
-	while ((ut = getutent()) != NULL)
+	while ((ut = getutent()) != NULL) {
 		if (ut->ut_pid == pid && ut->ut_line[0] && ut->ut_id[0]
 		 && (ut->ut_type == LOGIN_PROCESS || ut->ut_type == USER_PROCESS)
 		) {
@@ -70,6 +70,7 @@ static void read_or_build_utent(struct utmp *utptr, int run_by_root)
 				memset(utptr->ut_host, 0, sizeof(utptr->ut_host));
 			return;
 		}
+	}
 
 // Why? Do we require non-root to exec login from another
 // former login process (e.g. login shell)? Some login's have

networking/telnetd.c

@@ -74,11 +74,11 @@ struct globals {
    string of characters fit for the terminal.  Do this by packing
    all characters meant for the terminal sequentially towards the end of buf.
 
-   Return a pointer to the beginning of the characters meant for the terminal.
+   Return a pointer to the beginning of the characters meant for the terminal
    and make *num_totty the number of characters that should be sent to
    the terminal.
 
-   Note - If an IAC (3 byte quantity) starts before (bf + len) but extends
+   Note - if an IAC (3 byte quantity) starts before (bf + len) but extends
    past (bf + len) then that IAC will be left unprocessed and *processed
    will be less than len.