Initial import of the CDE 2.1.30 sources from the Open Group.

cde/lib/csa/iso8601.c

@@ -0,0 +1,319 @@
+/* $TOG: iso8601.c /main/2 1997/12/29 10:46:50 bill $ */
+/*
+ *  (c) Copyright 1993, 1994 Hewlett-Packard Company
+ *  (c) Copyright 1993, 1994 International Business Machines Corp.
+ *  (c) Copyright 1993, 1994 Novell, Inc.
+ *  (c) Copyright 1993, 1994 Sun Microsystems, Inc.
+ */
+
+#include <EUSCompat.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <time.h>
+#include <string.h>
+#include "iso8601.h"
+
+static void
+set_timezone(char *tzname)
+{
+        static char tzenv[BUFSIZ];
+ 
+        if (tzname==NULL)
+		system("unset TZ\n");
+        else {
+                sprintf(tzenv, "TZ=%s", tzname);
+                (void) putenv(tzenv);
+                tzset();
+        }
+}
+
+static int
+validate_iso8601(char *buf)
+{
+	/* validation rules:
+         *             - sscanf returns # of matches, which must be 6.
+         *             - crude range check on each numerical value scanned.
+         *             - length of input is fixed: strlen("CCYYMMDDThhmmssZ")
+         *             - last char must be Z, indicating UTC time
+         */
+	int	year, month, day, hour, min, sec;
+	int	scan_ret=0;
+static  char	tmp[] = "CCYYMMDDThhmmssZ";
+
+	scan_ret=sscanf(buf, "%4d%2d%2dT%2d%2d%2dZ",
+	    &year, &month, &day, &hour, &min, &sec);
+
+	/* the rules:  if any fail, whole test fails so return */
+	if (strlen(buf) != strlen(tmp)) return (-1);
+	if (buf[strlen(buf)-1] != 'Z')	return (-1);
+	if (scan_ret != 6)		return (-1);
+	if ((year<1970) || (year>2038))	return (-1);
+	if ((month<1) || (month>12))	return (-1);
+	if ((day<1) || (day>31))	return (-1);
+	if ((hour<0) || (hour>24))	return (-1);
+	if ((min<0) || (min>59))	return (-1);
+	if ((sec<0) || (sec>59))	return (-1);
+
+	return (0);
+}
+
+/*
+ * _csa_iso8601_to_tick - convert a standard date/time string to a tick
+ *
+ * Note 1:This function supports a limited subset of the iso8601 standard.
+ *	  Only one of the variations described by the standard is
+ *        supported, namely:
+ *
+ *		CCYYMMDDThhmmssZ
+ *
+ *        ...known in the standard as "Complete Representation, Basic Format"
+ *        for calendar date and "Coordinated Universal Time (UTC), Basic Format"
+ *        for time.
+ *
+ *	  This can carry all the information required for date+time by
+ *	  the CDE 1.0 Calendar component.  More general support, if ever
+ *	  needed (say for interoperability or finer granularity) can be
+ *	  implemented inside this function without modifying its interface.
+ *
+ * Note 2:All output time information is in UTC, and all input 
+ *        time information is assumed to be pre-converted to UTC.
+ *
+ *	  dac 19940728T224055Z  :-)
+ */ 
+int
+_csa_iso8601_to_tick(char *buf, time_t *tick_out)
+{
+	int		year, month, day, hour, min, sec;
+	struct tm	time_str;
+	char		tz_orig[BUFSIZ];
+	boolean_t	orig_tzset = B_FALSE;
+	int 		scan_ret=0;
+
+	scan_ret=sscanf(buf, "%4d%2d%2dT%2d%2d%2dZ",
+	    &year, &month, &day, &hour, &min, &sec);
+
+	if (validate_iso8601(buf) != 0)
+		return(-1);
+
+	time_str.tm_year	= year - 1900;
+	time_str.tm_mon		= month - 1;
+	time_str.tm_mday	= day;
+	time_str.tm_hour	= hour;
+	time_str.tm_min		= min;
+	time_str.tm_sec		= sec;
+	time_str.tm_isdst	= -1;
+
+	if (getenv("TZ")) {
+		strncpy(tz_orig, getenv("TZ"), sizeof(tz_orig));
+		tz_orig[sizeof(tz_orig)-1] = '\0';
+		orig_tzset = B_TRUE;
+	}
+
+#ifdef __osf__
+	set_timezone("GMT0");
+#else
+	set_timezone("GMT");
+#endif
+
+	*tick_out = mktime(&time_str);
+
+	if (orig_tzset == B_TRUE)
+		set_timezone(tz_orig);
+	else
+		set_timezone(NULL);
+
+	if (*tick_out != (long)-1)
+		return(0);
+	else
+		return(-1);
+}
+
+/*
+ * _csa_tick_to_iso8601 - convert from tick to iso8601 time string
+ *
+ * Note 1: Similar comments to the above.  This function complements
+ *         _csa_iso8601_to_tick, providing bi-directional conversion.
+ *
+ * Note 2: All input and output time information is UTC.
+ */
+int
+_csa_tick_to_iso8601(time_t tick, char *buf_out)
+{
+	struct tm	*time_str;
+	time_t		tk=tick;
+	char 		tz_orig[BUFSIZ];
+	boolean_t	orig_tzset = B_FALSE;
+
+	/* tick must be +ve to be valid */
+	if (tick < 0) {
+	   return(-1);
+	}
+
+	if (getenv("TZ")) {
+		strncpy(tz_orig, getenv("TZ"), sizeof(tz_orig));
+		tz_orig[sizeof(tz_orig)-1] = '\0';
+		orig_tzset = B_TRUE;
+	}
+
+#ifdef __osf__
+	set_timezone("GMT0");
+#else
+	set_timezone("GMT");
+#endif
+
+	time_str = localtime(&tk);
+
+	if (orig_tzset == B_TRUE)
+		set_timezone(tz_orig);
+	else
+		set_timezone(NULL);
+
+	/* format string forces fixed width (zero-padded) fields */
+	sprintf(buf_out, "%04d%02d%02dT%02d%02d%02dZ",
+		time_str->tm_year + 1900,
+		time_str->tm_mon + 1,
+		time_str->tm_mday,
+		time_str->tm_hour,
+		time_str->tm_min,
+		time_str->tm_sec);
+
+	return (0);
+}
+
+/*
+ * Convert iso8601 date time range to a start tick and an end tick
+ *
+ * iso8601 range is:
+ *                   <start> "/" <end>
+ *
+ * start and end are iso8601 strings in CCYYMMDDThhmmssZ format.
+ */
+
+int
+_csa_iso8601_to_range(char *buf, time_t *start, time_t *end)
+{
+    int nchars;
+    char tmpstr[BUFSIZ];
+    char *p;
+
+    if ((p = strchr(buf, '/')) == NULL) {
+        return (-1);
+    }
+
+    nchars=(p-buf);
+    strncpy(tmpstr, buf, (size_t)nchars);
+    tmpstr[nchars]='\0';
+
+    if (_csa_iso8601_to_tick(tmpstr, start) != 0) {
+        return (-1);
+    }
+
+    p++;
+    if (_csa_iso8601_to_tick(p, end) != 0) {
+        return (-1);
+    }
+
+    if (end < start)
+	return (-1);
+    else
+	return(0);
+}
+
+/*
+ * Convert time range specified as start/end ticks to iso8601 format
+ *
+ * iso8601 result is:
+ *                   <start> "/" <end>
+ *
+ * start and end are iso8601 strings in CCYYMMDDThhmmssZ format.
+ */
+int
+_csa_range_to_iso8601(time_t start, time_t end, char *buf)
+{
+    char tmpstr1[BUFSIZ], tmpstr2[BUFSIZ];
+
+    /* validate: ticks must be +ve, and end can't preceed start */
+    if ((start < 0) || (end < 0) || (end < start)) {
+        return(-1);
+    }
+
+    if (_csa_tick_to_iso8601(start, tmpstr1) != 0) {
+        return (-1);
+    }
+    if (_csa_tick_to_iso8601(end, tmpstr2) != 0) {
+        return (-1);
+    }
+
+    if (sprintf(buf, "%s/%s", tmpstr1, tmpstr2) < 0) {
+        return (-1);
+    }
+    else
+        return(0);
+}
+
+static int
+not_sign(char c)
+{
+   if ((c=='+') || (c=='-'))
+      return (0);
+   else
+      return (1);
+}
+
+/*
+ * This converts from a string representation of a quantity of time,
+ * to (signed) integer number of * seconds.
+ *   The first character (byte) must be a '+' or * a '-', indicating
+ * the sense of the period.  This can be used however you like - it's
+ * just a way of carrying round the sign, while keeping the main part
+ * of the string in ISO 8601.
+ *   The string must be in the format described by ISO 8601, clause
+ * 5.5.1 (b), with the added restriction that only seconds may be specified.
+ * format: [+/-]PTnS
+ */
+int
+_csa_iso8601_to_duration(char *buf, time_t *sec)
+{
+   /* buf must begin with '+' or '-', then 'P', end with 'S' */
+   char	sign, *ptr, *ptr2, *numptr;
+   int	num=0;
+
+   ptr2 = ptr = buf;
+   sign = *ptr++;
+
+   if (not_sign(sign)) {
+	if (*ptr2++ != 'P' || *ptr2++ != 'T') {
+		return (-1);
+	}
+   } else if (not_sign(sign) || *ptr++ != 'P' || *ptr++ != 'T') {
+	return (-1);
+   }
+
+   if (not_sign(sign))
+	ptr = ptr2;
+
+   numptr = ptr;
+   while (*ptr >= '0' && *ptr <= '9') ptr++;
+
+   if (numptr == ptr || !(*ptr && *ptr++ == 'S' && *ptr == NULL))
+	return (-1);
+   else {
+	num = atoi(numptr);
+	*sec = (sign == '-') ? -num : num;
+	return (0);
+   }
+}
+
+/*
+ * This converts from a (signed) integer number of seconds to a string
+ * representation.  The string format is a sign character followed by
+ * an IS0 8601 string as described above for _csa_iso8601_to_duration.
+ */
+int
+_csa_duration_to_iso8601(time_t sec, char *buf)
+{
+   sprintf(buf, "%cPT%dS", (sec < 0) ? '-': '+', abs(sec));
+   return(0);
+}
+