summaryrefslogtreecommitdiffstats
path: root/libmisc/gettime.c
diff options
context:
space:
mode:
Diffstat (limited to 'libmisc/gettime.c')
-rw-r--r--libmisc/gettime.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/libmisc/gettime.c b/libmisc/gettime.c
new file mode 100644
index 0000000..0e25a4b
--- /dev/null
+++ b/libmisc/gettime.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2017, Chris Lamb
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the copyright holders or contributors may not be used to
+ * endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include "defines.h"
+#include "prototypes.h"
+
+/*
+ * gettime() returns the time as the number of seconds since the Epoch
+ *
+ * Like time(), gettime() returns the time as the number of seconds since the
+ * Epoch, 1970-01-01 00:00:00 +0000 (UTC), except that if the SOURCE_DATE_EPOCH
+ * environment variable is exported it will use that instead.
+ */
+/*@observer@*/time_t gettime ()
+{
+ char *endptr;
+ char *source_date_epoch;
+ time_t fallback;
+ unsigned long long epoch;
+
+ fallback = time (NULL);
+ source_date_epoch = shadow_getenv ("SOURCE_DATE_EPOCH");
+
+ if (!source_date_epoch)
+ return fallback;
+
+ errno = 0;
+ epoch = strtoull (source_date_epoch, &endptr, 10);
+ if ((errno == ERANGE && (epoch == ULLONG_MAX || epoch == 0))
+ || (errno != 0 && epoch == 0)) {
+ fprintf (stderr,
+ _("Environment variable $SOURCE_DATE_EPOCH: strtoull: %s\n"),
+ strerror(errno));
+ } else if (endptr == source_date_epoch) {
+ fprintf (stderr,
+ _("Environment variable $SOURCE_DATE_EPOCH: No digits were found: %s\n"),
+ endptr);
+ } else if (*endptr != '\0') {
+ fprintf (stderr,
+ _("Environment variable $SOURCE_DATE_EPOCH: Trailing garbage: %s\n"),
+ endptr);
+ } else if (epoch > ULONG_MAX) {
+ fprintf (stderr,
+ _("Environment variable $SOURCE_DATE_EPOCH: value must be smaller than or equal to %lu but was found to be: %llu\n"),
+ ULONG_MAX, epoch);
+ } else if (epoch > fallback) {
+ fprintf (stderr,
+ _("Environment variable $SOURCE_DATE_EPOCH: value must be smaller than or equal to the current time (%lu) but was found to be: %llu\n"),
+ fallback, epoch);
+ } else {
+ /* Valid */
+ return (time_t)epoch;
+ }
+
+ return fallback;
+}