sbase

suckless unix tools
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commit 1d28fbd6cfb38fa50976b2f2ff995b376638798e
parent 0ba81a0f84aa555592ff890510323cd021ca9100
Author: Michael Forney <mforney@mforney.org>
Date:   Sat, 16 May 2015 04:57:25 +0000

mv, cp: Preserve nanosecond timestamps

Otherwise, we run into problems in a typical autoconf-based build
system:

  - config.status is created at some point between two seconds.
  - config.status is run, generating Makefile by first writing to a file
    in /tmp, and then mv-ing it to Makefile.
  - If this mv happens before the beginning of the next second, Makefile
    will be created with the same tv_sec as config.status, but with
    tv_nsec = 0.
  - When make runs, it sees that Makefile is older than config.status,
    and re-runs config.status to generate Makefile.

Diffstat:
Mlibutil/cp.c | 8++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/libutil/cp.c b/libutil/cp.c @@ -30,7 +30,7 @@ cp(const char *s1, const char *s2, int depth) FILE *f1, *f2; struct dirent *d; struct stat st; - struct utimbuf ut; + struct timespec times[2]; ssize_t r; int (*statf)(const char *, struct stat *); char target[PATH_MAX], ns1[PATH_MAX], ns2[PATH_MAX], *statf_name; @@ -154,9 +154,9 @@ cp(const char *s1, const char *s2, int depth) if (cp_aflag || cp_pflag) { /* timestamp and owner*/ if (!S_ISLNK(st.st_mode)) { - ut.actime = st.st_atime; - ut.modtime = st.st_mtime; - utime(s2, &ut); + times[0] = st.st_atim; + times[1] = st.st_mtim; + utimensat(AT_FDCWD, s2, times, 0); if (chown(s2, st.st_uid, st.st_gid) < 0) { weprintf("chown %s:", s2);