new utilities.
the .C files compile but are renamed to avoid building automatically.
diff --git a/src/cmd/calendar.c b/src/cmd/calendar.c
new file mode 100644
index 0000000..6202c5a
--- /dev/null
+++ b/src/cmd/calendar.c
@@ -0,0 +1,195 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <regexp.h>
+#include <ctype.h>
+
+typedef struct Date Date;
+struct Date {
+ Reprog *p; /* an RE to match this date */
+ Date *next; /* pointer to next in list */
+};
+
+enum{
+ Secondsperday = 24*60*60
+};
+
+Biobuf in;
+int debug, matchyear;
+
+Date *dates(Date**, Tm*);
+void upper2lower(char*, char*, int);
+void *alloc(unsigned int);
+
+void
+main(int argc, char *argv[])
+{
+ int i, fd, ahead;
+ long now;
+ char *line;
+ Tm *tm;
+ Date *first, *last, *d;
+ char buf[1024];
+
+ ahead = 0;
+ ARGBEGIN{
+ case 'y':
+ matchyear = 1;
+ break;
+ case 'd':
+ debug = 1;
+ break;
+ case 'p':
+ ahead = atoi(ARGF());
+ break;
+ default:
+ fprint(2, "usage: calendar [-y] [-d] [files ...]\n");
+ exits("usage");
+ }ARGEND;
+
+ /* make a list of dates */
+ now = time(0);
+ tm = localtime(now);
+ last = nil;
+ first = dates(&last, tm);
+ now += Secondsperday;
+ tm = localtime(now);
+ dates(&last, tm);
+ if(tm->wday == 6){
+ now += Secondsperday;
+ tm = localtime(now);
+ dates(&last, tm);
+ }
+ if(tm->wday == 0){
+ now += Secondsperday;
+ tm = localtime(now);
+ dates(&last, tm);
+ }
+ if(ahead){
+ now = time(0);
+ now += ahead * Secondsperday;
+ tm = localtime(now);
+ dates(&last, tm);
+ }
+
+ for(i=0; i<argc || (i==0 && argc==0); i++){
+ if(i==0 && argc==0)
+ snprint(buf, sizeof(buf),
+ "/usr/%s/lib/calendar", getuser());
+ else
+ strcpy(buf, argv[i]);
+ fd = open(buf, OREAD);
+ if(fd<0 || Binit(&in, fd, OREAD)<0){
+ fprint(2, "calendar: can't open %s: %r\n", buf);
+ exits("open");
+ }
+
+ /* go through the file */
+ while(line = Brdline(&in, '\n')){
+ line[Blinelen(&in) - 1] = 0;
+ upper2lower(buf, line, sizeof buf);
+ for(d=first; d; d=d->next)
+ if(regexec(d->p, buf, 0, 0)){
+ print("%s\n", line);
+ break;
+ }
+ }
+ close(fd);
+ }
+ exits("");
+}
+
+char *months[] =
+{
+ "january",
+ "february",
+ "march",
+ "april",
+ "may",
+ "june",
+ "july",
+ "august",
+ "september",
+ "october",
+ "november",
+ "december"
+};
+
+/*
+ * Generate two Date structures. First has month followed by day;
+ * second has day followed by month. Link them into list after
+ * last, and return the first.
+ */
+Date*
+dates(Date **last, Tm *tm)
+{
+ Date *first;
+ Date *nd;
+ char mo[128], buf[128];
+
+ if(utflen(months[tm->mon]) > 3)
+ snprint(mo, sizeof mo, "%3.3s(%s)?",
+ months[tm->mon], months[tm->mon]+3);
+ else
+ snprint(mo, sizeof mo, "%3.3s", months[tm->mon]);
+ if (matchyear)
+ snprint(buf, sizeof buf,
+ "(^| |\t)((%s( |\t)+)|(%d/))%d( |\t|$)(((%d|%d)( |\t|$))|[^0-9]|([0-9]+[^0-9 \t]))",
+ mo, tm->mon+1, tm->mday, tm->year+1900, tm->year%100);
+ else
+ snprint(buf, sizeof buf,
+ "(^| |\t)((%s( |\t)+)|(%d/))%d( |\t|$)",
+ mo, tm->mon+1, tm->mday);
+ if(debug)
+ print("%s\n", buf);
+
+ first = alloc(sizeof(Date));
+ if(*last)
+ (*last)->next = first;
+ first->p = regcomp(buf);
+
+ if (matchyear)
+ snprint(buf, sizeof buf,
+ "(^| |\t)%d( |\t)+(%s)( |\t|$)(((%d|%d)( |\t|$))|[^0-9]|([0-9]+[^0-9 \t]))",
+ tm->mday, mo, tm->year+1900, tm->year%100);
+ else
+ snprint(buf, sizeof buf,
+ "(^| |\t)%d( |\t)+(%s)( |\t|$)",
+ tm->mday, mo);
+ if(debug)
+ print("%s\n", buf);
+ nd = alloc(sizeof(Date));
+ nd->p = regcomp(buf);
+ nd->next = 0;
+ first->next = nd;
+ *last = nd;
+
+ return first;
+}
+
+/*
+ * Copy 'from' to 'to', converting to lower case
+ */
+void
+upper2lower(char *to, char *from, int len)
+{
+ while(--len>0 && *from!='\0')
+ *to++ = tolower(*from++);
+ *to = 0;
+}
+
+/*
+ * Call malloc and check for errors
+ */
+void*
+alloc(unsigned int n)
+{
+ void *p;
+
+ p = malloc(n);
+ if(p == 0){
+ fprint(2, "calendar: malloc failed: %r\n");
+ exits("malloc");
+ }
+ return p;
+}
