minix/commands/simple/calendar.c
2005-04-21 14:53:53 +00:00

230 lines
5 KiB
C
Executable file

/* calendar - reminder service Authors: S. & K. Hirabayashi */
/* Permission is hereby granted for nonprofit use. */
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <regexp.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <termcap.h>
#include <unistd.h>
#include <utime.h>
#include <stdio.h>
/* Change these two lines for your system needs. */
#define MAIL1 "/usr/bin/mail"
#define MAIL2 "/bin/mail"
#define PASSWD "/etc/passwd" /* system password file */
#define MAX_EXP 4 /* see date_exp() function */
char *mail; /* mail command path ("/bin/mail" etc) */
regexp *exp[MAX_EXP]; /* date expressions */
int nexp; /* # of the date expressions */
char calfile[PATH_MAX]; /* calendar file for the user */
int rflg; /* consult aged 'calendar' file and touch */
int mflg; /* mail (multi user) service */
char *cmd; /* the name of this command */
char buf[BUFSIZ];
_PROTOTYPE(int main, (int argc, char **argv));
_PROTOTYPE(void calendar, (void));
_PROTOTYPE(char *getstr, (char *s, int n));
_PROTOTYPE(int newaccess, (char *file));
_PROTOTYPE(void grep, (char *file, char *user));
_PROTOTYPE(int date_exp, (void));
_PROTOTYPE(char *date_pat, (time_t t));
_PROTOTYPE(void regerror, (char *s));
_PROTOTYPE(void error, (char *s, char *t));
int main(argc, argv)
int argc;
char **argv;
{
char *s;
cmd = *argv;
while (--argc > 0 && (*++argv)[0] == '-') {
s = argv[0] + 1;
if (*s == '\0')
mflg++; /* mail service */
else if (strcmp(s, "r") == 0)
rflg++, mflg++;
}
if (mflg) { /* check mailing agent */
if (access(MAIL1, X_OK) == 0)
mail = MAIL1;
else if (access(MAIL2, X_OK) == 0)
mail = MAIL2;
else
error("cannot find %s", MAIL1);
}
nexp = date_exp();
calendar();
exit(0);
}
void calendar()
{
int i;
char *s;
FILE *fp;
if (!mflg) {
grep("calendar", "");
return;
}
/* Mail sevice */
if ((fp = fopen(PASSWD, "r")) == (FILE *) NULL)
error("cannot open %s", PASSWD);
while (fgets(buf, BUFSIZ, fp) != (char *) NULL) {
for (i = 0, s = buf; *s && *s != '\n'; s++)
if (*s == ':') i++;
*s = '\0';
if (i != 6) error("illegal '/etc/passwd' format: %s", buf);
/* Calendar file = ${HOME}/calendar */
sprintf(calfile, "%s/%s", getstr(buf, 5), "calendar");
if ((access(calfile, R_OK) != 0) || (rflg && !newaccess(calfile)))
continue;
grep(calfile, getstr(buf, 0));
}
fclose(fp);
}
char *getstr(s, n)
char *s;
int n;
{
/* Returns the string value of the n-th field in the record (s) */
int i;
char *t;
static char str[512];
for (i = 0; i < n && *s; s++)
if (*s == ':') i++; /* field separator */
for (i = 0, t = str; *s && *s != ':' && i < 511; i++) *t++ = *s++;
*t = '\0';
return str;
}
int newaccess(file)
char *file; /* file name */
{
/* Check whether the file has been touched today. */
int r = 0;
struct tm *tm;
struct stat stbuf;
time_t clk;
char newdate[8], olddate[8];
time(&clk);
tm = localtime(&clk);
sprintf(newdate, "%02d%02d%02d", tm->tm_year, tm->tm_mon + 1, tm->tm_mday);
if (stat(file, &stbuf) == -1) error("cannot stat %s", file);
tm = localtime(&stbuf.st_mtime);
sprintf(olddate, "%02d%02d%02d", tm->tm_year, tm->tm_mon + 1, tm->tm_mday);
if (strcmp(newdate, olddate) != 0) {
utime(file, NULL); /* touch */
r++;
}
return r;
}
void grep(file, user)
char *file, *user;
{ /* grep 'exp[]' [| mail user] */
int i;
char command[128]; /* mail command */
FILE *ifp, *ofp;
if ((ifp = fopen(file, "r")) == (FILE *) NULL)
error("cannot open %s", file);
if (*user != '\0') {
sprintf(command, "%s %s", mail, user);
ofp = (FILE *) NULL;
} else {
ofp = stdout;
}
while (fgets(buf, BUFSIZ, ifp) != (char *) NULL) {
for (i = 0; i < nexp; i++) {
if (regexec(exp[i], buf, 1)) {
if ((ofp == (FILE *) NULL) &&
(ofp = popen(command, "w")) == (FILE *) NULL)
error("cannot popen %s", mail);
fputs(buf, ofp);
break;
}
}
}
fclose(ifp);
if (ofp == stdout)
fflush(ofp);
else if (ofp != (FILE *) NULL)
pclose(ofp);
}
int date_exp()
{
/* Set compiled regular expressions into the exp[] array. */
static int n[] = {2, 2, 2, 2, 2, 4, 3};
int i, r, wday;
time_t clk;
time(&clk);
wday = localtime(&clk)->tm_wday;
r = n[wday];
if (r > MAX_EXP) error("too many date expressions", "");
for (i = 0; i < r; i++) {
exp[i] = regcomp(date_pat(clk));
clk += 60 * 60 * 24L; /* 24 hours */
}
return(r);
}
char *date_pat(t)
time_t t;
{ /* returns date expression for the time (t) */
static char *month[] = {
"[Jj]an", "[Ff]eb", "[Mm]ar", "[Aa]pr", "[Mm]ay", "[Jj]un",
"[Jj]ul", "[Aa]ug", "[Ss]ep", "[Oo]ct", "[Nn]ov", "[Dd]ec"
};
static char str[512];
struct tm *tm;
tm = localtime(&t);
sprintf(str,
"(^|[ \t(,;])(((%s[^ \t]*[ \t])|0*%d/|\\*/)(0*%d|\\*))([^0123456789]|$)",
month[tm->tm_mon], tm->tm_mon + 1, tm->tm_mday);
return str;
}
void regerror(s)
char *s;
{ /* regcomp() needs this */
error("REGULAR EXPRESSION ERROR (%s)", s);
}
void error(s, t)
char *s, *t;
{
fprintf(stderr, "%s: ", cmd);
fprintf(stderr, s, t);
fprintf(stderr, "\n");
exit(1);
}