Fix interval timers by forcing TZ to UTC, else some strftime formats

print strange offsets.

While there rework the main loop to only use localtime and now.
Calculate the relative time offset for -m mode just once at startup.
OK sthen@ job@

diff --git a/usr.bin/ts/ts.c b/usr.bin/ts/ts.c
index d2067e4..6f0e7be 100644 (file)
--- a/usr.bin/ts/ts.c
+++ b/usr.bin/ts/ts.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ts.c,v 1.2 2022/06/29 16:01:10 job Exp $      */
+/*     $OpenBSD: ts.c,v 1.3 2022/06/30 07:42:50 claudio Exp $  */
 /*
  * Copyright (c) 2022 Job Snijders <job@openbsd.org>
  * Copyright (c) 2022 Claudio Jeker <claudio@openbsd.org>
@@ -40,8 +40,8 @@ main(int argc, char *argv[])
 {
        int iflag, mflag, sflag;
        int ch, prev;
-       struct timespec rstart, start, now, elapsed;
-       struct tm *lt, tm;
+       struct timespec roff, start, now;
+       struct tm *tm;
        int clock = CLOCK_REALTIME;
 
        if (pledge("stdio", NULL) == -1)
@@ -88,34 +88,27 @@ main(int argc, char *argv[])
        if ((outbuf = calloc(1, bufsize)) == NULL)
                err(1, NULL);
 
-       clock_gettime(CLOCK_REALTIME, &rstart);
-       clock_gettime(CLOCK_MONOTONIC, &start);
+       /* force UTC for interval calculations */
+       if (iflag || sflag)
+               if (setenv("TZ", "UTC", 1) == -1)
+                       err(1, "setenv UTC");
+
+       clock_gettime(CLOCK_REALTIME, &roff);
+       clock_gettime(clock, &start);
+       timespecsub(&roff, &start, &roff);
 
        for (prev = '\n'; (ch = getchar()) != EOF; prev = ch) {
                if (prev == '\n') {
-                       if (clock_gettime(clock, &now))
-                               err(1, "clock_gettime");
-                       if (iflag || sflag) {
-                               timespecsub(&now, &start, &elapsed);
-                               if (gmtime_r(&elapsed.tv_sec, &tm) == NULL)
-                                       err(1, "gmtime_r");
-                               if (iflag)
-                                       if (clock_gettime(clock, &start))
-                                               err(1, "clock_gettime");
-                               fmtfmt(&tm, elapsed.tv_nsec);
-                       } else if (mflag) {
-                               timespecsub(&now, &start, &elapsed);
-                               timespecadd(&rstart, &elapsed, &now);
-                               lt = localtime(&now.tv_sec);
-                               if (lt == NULL)
-                                       err(1, "localtime");
-                               fmtfmt(lt, now.tv_nsec);
-                       } else {
-                               lt = localtime(&now.tv_sec);
-                               if (lt == NULL)
-                                       err(1, "localtime");
-                               fmtfmt(lt, now.tv_nsec);
-                       }
+                       clock_gettime(clock, &now);
+                       if (iflag || sflag)
+                               timespecsub(&now, &start, &now);
+                       else if (mflag)
+                               timespecadd(&now, &roff, &now);
+                       if (iflag)
+                               clock_gettime(clock, &start);
+                       if ((tm = localtime(&now.tv_sec)) == NULL)
+                               err(1, "localtime/gmtime");
+                       fmtfmt(tm, now.tv_nsec);
                }
                if (putchar(ch) == EOF)
                        break;