sbase/touch.c
Michael Forney 2e5f1281ed touch: Use special UTIME_NOW and UTIME_OMIT values
This allows users to touch files they have write access to, but aren't the
owner.

Also, remove utime.h include (not necessary since
4132561c17), and make sure to check the return
value of localtime (potentially preventing a NULL pointer derefence).
2016-07-09 10:17:16 +01:00

165 lines
2.8 KiB
C

/* See LICENSE file for copyright and license details. */
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "util.h"
static int aflag;
static int cflag;
static int mflag;
static struct timespec times[2] = {{.tv_nsec = UTIME_NOW}};
static void
touch(const char *file)
{
int fd;
struct stat st;
if (stat(file, &st) < 0) {
if (errno != ENOENT)
eprintf("stat %s:", file);
if (cflag)
return;
} else {
if (utimensat(AT_FDCWD, file, times, 0) < 0)
eprintf("utimensat %s:", file);
return;
}
if ((fd = open(file, O_WRONLY | O_CREAT | O_EXCL, 0666)) < 0)
eprintf("open %s:", file);
close(fd);
touch(file);
}
static time_t
parsetime(char *str)
{
time_t now;
struct tm *cur, t = { 0 };
int zulu = 0;
char *format;
size_t len = strlen(str);
if ((now = time(NULL)) == -1)
eprintf("time:");
if (!(cur = localtime(&now)))
eprintf("localtime:");
t.tm_isdst = -1;
switch (len) {
/* -t flag argument */
case 8:
t.tm_year = cur->tm_year;
format = "%m%d%H%M";
break;
case 10:
format = "%y%m%d%H%M";
break;
case 11:
t.tm_year = cur->tm_year;
format = "%m%d%H%M.%S";
break;
case 12:
format = "%Y%m%d%H%M";
break;
case 13:
format = "%y%m%d%H%M.%S";
break;
case 15:
format = "%Y%m%d%H%M.%S";
break;
/* -d flag argument */
case 19:
format = "%Y-%m-%dT%H:%M:%S";
break;
case 20:
/* only Zulu-timezone supported */
if (str[19] != 'Z')
eprintf("Invalid time zone\n");
str[19] = 0;
zulu = 1;
format = "%Y-%m-%dT%H:%M:%S";
break;
default:
eprintf("Invalid date format length\n", str);
}
if (!strptime(str, format, &t))
eprintf("strptime %s: Invalid date format\n", str);
if (zulu) {
t.tm_hour += t.tm_gmtoff / 60;
t.tm_gmtoff = 0;
t.tm_zone = "Z";
}
return mktime(&t);
}
static void
usage(void)
{
eprintf("usage: %s [-acm] [-d time | -r ref_file | -t time | -T time] "
"file ...\n", argv0);
}
int
main(int argc, char *argv[])
{
struct stat st;
char *ref = NULL;
ARGBEGIN {
case 'a':
aflag = 1;
break;
case 'c':
cflag = 1;
break;
case 'd':
case 't':
times[0].tv_sec = parsetime(EARGF(usage()));
times[0].tv_nsec = 0;
break;
case 'm':
mflag = 1;
break;
case 'r':
ref = EARGF(usage());
if (stat(ref, &st) < 0)
eprintf("stat '%s':", ref);
times[0] = st.st_atim;
times[1] = st.st_mtim;
break;
case 'T':
times[0].tv_sec = estrtonum(EARGF(usage()), 0, LLONG_MAX);
times[0].tv_nsec = 0;
break;
default:
usage();
} ARGEND
if (!argc)
usage();
if (!aflag && !mflag)
aflag = mflag = 1;
if (!ref)
times[1] = times[0];
if (!aflag)
times[0].tv_nsec = UTIME_OMIT;
if (!mflag)
times[1].tv_nsec = UTIME_OMIT;
for (; *argv; argc--, argv++)
touch(*argv);
return 0;
}