Make the ways of using output stream consistent in usage()

[thirdparty/util-linux.git] / login-utils / utmpdump.c

diff --git a/login-utils/utmpdump.c b/login-utils/utmpdump.c
index 5cc87834aef32e0897859cdda364363986891bd4..ce9ad718b2a5994fa6060a7ce7f99b486dc03b5b 100644 (file)
--- a/login-utils/utmpdump.c
+++ b/login-utils/utmpdump.c
@@ -74,8 +74,16 @@ static time_t strtotime(const char *s_time)
 static suseconds_t strtousec(const char *s_time)
 {
        const char *s = strchr(s_time, ',');
-       if (s)
-               return (suseconds_t) atoi(s + 1);
+
+       if (s && *++s) {
+               suseconds_t us;
+               char *end = NULL;
+
+               errno = 0;
+               us = strtol(s, &end, 10);
+               if (errno == 0 && end && end > s)
+                       return us;
+       }
        return 0;
 }
 
@@ -100,7 +108,7 @@ static void print_utline(struct utmpx *ut, FILE *out)
                addr_string = inet_ntop(AF_INET, &(ut->ut_addr_v6), buffer, sizeof(buffer));
 
        tv.tv_sec = ut->ut_tv.tv_sec;
-       tv.tv_usec = ut->ut_tv.tv_usec;
+       tv.tv_usec = ut->ut_tv.tv_usec < (int32_t) USEC_PER_SEC ? ut->ut_tv.tv_usec : 0;
 
        if (strtimeval_iso(&tv, ISO_TIMESTAMP_COMMA_GT, time_string,
                           sizeof(time_string)) != 0)
@@ -169,6 +177,9 @@ static int follow_by_inotify(FILE *in, const char *filename, FILE *out)
        size = ftello(in);
        fclose(in);
 
+       if (size < 0)
+               err(EXIT_FAILURE, _("%s: cannot get file position"), filename);
+
        wd = inotify_add_watch(fd, filename, EVENTS);
        if (wd == -1)
                err(EXIT_FAILURE, _("%s: cannot add inotify watch."), filename);
@@ -219,15 +230,14 @@ static FILE *dump(FILE *in, const char *filename, int follow, FILE *out)
 #ifdef HAVE_INOTIFY_INIT
        if (follow_by_inotify(in, filename, out) == 0)
                return NULL;                            /* file already closed */
-       else
 #endif
-               /* fallback for systems without inotify or with non-free
-                * inotify instances */
-               for (;;) {
-                       while (fread(&ut, sizeof(ut), 1, in) == 1)
-                               print_utline(&ut, out);
-                       sleep(1);
-               }
+       /* fallback for systems without inotify or with non-free
+        * inotify instances */
+       for (;;) {
+               while (fread(&ut, sizeof(ut), 1, in) == 1)
+                       print_utline(&ut, out);
+               sleep(1);
+       }
 
        return in;
 }
@@ -264,7 +274,7 @@ static int gettok(char *line, char *dest, int size, int eatspace)
 static void undump(FILE *in, FILE *out)
 {
        struct utmpx ut;
-       char s_addr[INET6_ADDRSTRLEN + 1], s_time[29], *linestart, *line;
+       char s_addr[INET6_ADDRSTRLEN + 1], s_time[29] = {}, *linestart, *line;
 
        linestart = xmalloc(1024 * sizeof(*linestart));
        s_time[28] = 0;
@@ -272,7 +282,12 @@ static void undump(FILE *in, FILE *out)
        while (fgets(linestart, 1023, in)) {
                line = linestart;
                memset(&ut, '\0', sizeof(ut));
-               sscanf(line, "[%hd] [%d] [%4c] ", &ut.ut_type, &ut.ut_pid, ut.ut_id);
+
+               if (sscanf(line, "[%hd] [%d] [%4c] ",
+                               &ut.ut_type, &ut.ut_pid, ut.ut_id) != 3) {
+                       warnx(_("parse error: %s"), line);
+                       continue;
+               }
 
                line += 19;
                line += gettok(line, ut.ut_user, sizeof(ut.ut_user), 1);
@@ -309,9 +324,9 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(_(" -f, --follow         output appended data as the file grows\n"), out);
        fputs(_(" -r, --reverse        write back dumped data into utmp file\n"), out);
        fputs(_(" -o, --output <file>  write to file instead of standard output\n"), out);
-       printf(USAGE_HELP_OPTIONS(22));
+       fprintf(out, USAGE_HELP_OPTIONS(22));
 
-       printf(USAGE_MAN_TAIL("utmpdump(1)"));
+       fprintf(out, USAGE_MAN_TAIL("utmpdump(1)"));
        exit(EXIT_SUCCESS);
 }
 
@@ -334,7 +349,7 @@ int main(int argc, char **argv)
        setlocale(LC_ALL, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
-       atexit(close_stdout);
+       close_stdout_atexit();
 
        while ((c = getopt_long(argc, argv, "fro:hV", longopts, NULL)) != -1) {
                switch (c) {
@@ -355,10 +370,8 @@ int main(int argc, char **argv)
 
                case 'h':
                        usage();
-                       break;
                case 'V':
-                       printf(UTIL_LINUX_VERSION);
-                       return EXIT_SUCCESS;
+                       print_version(EXIT_SUCCESS);
                default:
                        errtryhelp(EXIT_FAILURE);
                }
@@ -367,6 +380,10 @@ int main(int argc, char **argv)
        if (!out)
                out = stdout;
 
+       if (follow && (out != stdout || !isatty(STDOUT_FILENO))) {
+               setvbuf(out, NULL, _IOLBF, 0);
+       }
+
        if (optind < argc) {
                filename = argv[optind];
                in = fopen(filename, "r");