[src/trunk]: src/usr.bin/make filemon_read: report error if lseek fails

[sjg <sjg%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b75e34633bb5
branches:  trunk
changeset: 935138:b75e34633bb5
user:      sjg <sjg%NetBSD.org@localhost>
date:      Thu Jun 25 15:45:37 2020 +0000

description:
filemon_read: report error if lseek fails

Reviewed by: riastradh

diffstat:

 usr.bin/make/meta.c |  20 ++++++++++++--------
 1 files changed, 12 insertions(+), 8 deletions(-)

diffs (35 lines):

diff -r 51b296e942fb -r b75e34633bb5 usr.bin/make/meta.c
--- a/usr.bin/make/meta.c       Thu Jun 25 15:43:26 2020 +0000
+++ b/usr.bin/make/meta.c       Thu Jun 25 15:45:37 2020 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: meta.c,v 1.81 2020/04/03 03:32:28 sjg Exp $ */
+/*      $NetBSD: meta.c,v 1.82 2020/06/25 15:45:37 sjg Exp $ */
 
 /*
  * Implement 'meta' mode.
@@ -170,14 +170,18 @@
        return 0;
     }
     /* rewind */
-    (void)lseek(fd, (off_t)0, SEEK_SET);
+    if (lseek(fd, (off_t)0, SEEK_SET) < 0) {
+       error = errno;
+       warn("Could not rewind filemon");
+       fprintf(mfp, "\n");
+    } else {
+       error = 0;
+       fprintf(mfp, "\n-- filemon acquired metadata --\n");
 
-    error = 0;
-    fprintf(mfp, "\n-- filemon acquired metadata --\n");
-
-    while ((n = read(fd, buf, sizeof(buf))) > 0) {
-       if ((int)fwrite(buf, 1, n, mfp) < n)
-           error = EIO;
+       while ((n = read(fd, buf, sizeof(buf))) > 0) {
+           if ((int)fwrite(buf, 1, n, mfp) < n)
+               error = EIO;
+       }
     }
     fflush(mfp);
     if (close(fd) < 0)