Import sources from 2011-03-30 iso image

1 files changed, 141 insertions, 0 deletions

diff --git a/sys/src/ape/lib/ap/posix/tzset.c b/sys/src/ape/lib/ap/posix/tzset.c
new file mode 100755
index 000000000..8502c6d66
--- /dev/null
+++ b/sys/src/ape/lib/ap/posix/tzset.c
@@ -0,0 +1,141 @@
+#include <stdlib.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <time.h>
+#include <ctype.h>
+#include <string.h>
+#include <unistd.h>
+
+#define TZFILE	"/etc/TZ"
+
+static char TZ[128];
+static char std[32] = "GMT0";
+static char dst[32];
+char *tzname[2] = {
+	std, dst
+};
+time_t tzoffset, tzdstoffset;
+int tzdst = 0;
+
+static int
+offset(char *env, time_t *off)
+{
+	int n, sign;
+	size_t len, retlen;
+
+	retlen = 0;
+	sign = 1;
+	/*
+	 * strictly, no sign is allowed in the 'time' part of the
+	 * dst start/stop rules, but who cares?
+	 */
+	if (*env == '-' || *env == '+') {
+		if (*env++ == '-')
+			sign = -1;
+		retlen++;
+	}
+	if ((len = strspn(env, ":0123456789")) == 0)
+		return 0;
+	retlen += len;
+	for (*off = 0; len && isdigit(*env); len--)		/* hours */
+		*off = *off*10 + (*env++ - '0')*60*60;
+	if (len) {
+		if (*env++ != ':')
+			return 0;
+		len--;
+	}
+	for (n = 0; len && isdigit(*env); len--)		/* minutes */
+		n = n*10 + (*env++ - '0')*60;
+	*off += n;
+	if (len) {
+		if (*env++ != ':')
+			return 0;
+		len--;
+	}
+	for (n = 0; len && isdigit(*env); len--)		/* seconds */
+		n = n*10 + (*env++ - '0');
+	*off = (*off + n)*sign;
+	return retlen;
+}
+
+/*
+ * TZ=stdoffset[dst[offset][,start[/time],end[/time]]]
+ */
+void
+tzset(void)
+{
+	char *env, *p, envbuf[128];
+	int fd, i;
+	size_t len, retlen;
+	time_t off;
+
+	/*
+	 * get the TZ environment variable and check for validity.
+	 * the implementation-defined manner for dealing with the
+	 * leading ':' format is to reject it.
+	 * if it's ok, stash a copy away for quick comparison next time.
+	 */
+	if ((env = getenv("TZ")) == 0) {
+		if ((fd = open(TZFILE, O_RDONLY)) == -1)
+			return;
+		if (read(fd, envbuf, sizeof(envbuf)-1) == -1) {
+			close(fd);
+			return;
+		}
+		close(fd);
+		for (i = 0; i < sizeof(envbuf); i++) {
+			if (envbuf[i] != '\n')
+				continue;
+			envbuf[i] = '\0';
+			break;
+		}
+		env = envbuf;
+	}
+	if (strcmp(env, TZ) == 0)
+		return;
+	if (*env == 0 || *env == ':')
+		return;
+	strncpy(TZ, env, sizeof(TZ)-1);
+	TZ[sizeof(TZ)-1] = 0;
+	/*
+	 * get the 'std' string.
+	 * before committing, check there is a valid offset.
+	 */
+	if ((len = strcspn(env, ":0123456789,-+")) == 0)
+		return;
+	if ((retlen = offset(env+len, &off)) == 0)
+		return;
+	for (p = std, i = len+retlen; i; i--)
+		*p++ = *env++;
+	*p = 0;
+	tzoffset = -off;
+	/*
+	 * get the 'dst' string (if any).
+	 */
+	if (*env == 0 || (len = strcspn(env, ":0123456789,-+")) == 0)
+		return;
+	for (p = dst; len; len--)
+		*p++ = *env++;
+	*p = 0;
+	/*
+	 * optional dst offset.
+	 * default is one hour.
+	 */
+	tzdst = 1;
+	if (retlen = offset(env+len, &off)) {
+		tzdstoffset = -off;
+		env += retlen;
+	}
+	else
+		tzdstoffset = tzoffset + 60*60;
+	/*
+	 * optional rule(s) for start/end of dst.
+	 */
+	if (*env == 0 || *env != ',' || *(env+1) == 0)
+		return;
+	env++;
+	/*
+	 * we could go on...
+	 * but why bother?
+	 */
+}