commands/simple/calendar.c

   1 /* calendar - reminder service          Authors: S. & K. Hirabayashi */
   2
   3 /* Permission is hereby granted for nonprofit use. */
   4
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <time.h>
   8 #include <regexp.h>
   9 #include <limits.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <termcap.h>
  13 #include <unistd.h>
  14 #include <utime.h>
  15 #include <stdio.h>
  16
  17 /* Change these two lines for your system needs. */
  18 #define MAIL1   "/usr/bin/mail"
  19 #define MAIL2   "/bin/mail"
  20 #define PASSWD  "/etc/passwd"   /* system password file */
  21 #define MAX_EXP         4       /* see date_exp() function */
  22
  23 char *mail;                     /* mail command path ("/bin/mail" etc) */
  24 regexp *exp[MAX_EXP];           /* date expressions */
  25 int nexp;                       /* # of the date expressions */
  26 char calfile[PATH_MAX];         /* calendar file for the user */
  27
  28 int rflg;                       /* consult aged 'calendar' file and touch */
  29 int mflg;                       /* mail (multi user) service */
  30 char *cmd;                      /* the name of this command */
  31 char buf[BUFSIZ];
  32
  33 _PROTOTYPE(int main, (int argc, char **argv));
  34 _PROTOTYPE(void calendar, (void));
  35 _PROTOTYPE(char *getstr, (char *s, int n));
  36 _PROTOTYPE(int newaccess, (char *file));
  37 _PROTOTYPE(void grep, (char *file, char *user));
  38 _PROTOTYPE(int date_exp, (void));
  39 _PROTOTYPE(char *date_pat, (time_t t));
  40 /*
  41 _PROTOTYPE(void regerror, (char *s));
  42 */
  43 _PROTOTYPE(void error, (char *s, char *t));
  44
  45 int main(argc, argv)
  46 int argc;
  47 char **argv;
  48 {
  49   char *s;
  50
  51   cmd = *argv;
  52   while (--argc > 0 && (*++argv)[0] == '-') {
  53         s = argv[0] + 1;
  54         if (*s == '\0')
  55                 mflg++;         /* mail service */
  56         else if (strcmp(s, "r") == 0)
  57                 rflg++, mflg++;
  58   }
  59
  60   if (mflg) {                   /* check mailing agent */
  61         if (access(MAIL1, X_OK) == 0)
  62                 mail = MAIL1;
  63         else if (access(MAIL2, X_OK) == 0)
  64                 mail = MAIL2;
  65         else
  66                 error("cannot find %s", MAIL1);
  67   }
  68   nexp = date_exp();
  69   calendar();
  70   exit(0);
  71 }
  72
  73 void calendar()
  74 {
  75   int i;
  76   char *s;
  77   FILE *fp;
  78
  79   if (!mflg) {
  80         grep("calendar", "");
  81         return;
  82   }
  83
  84   /* Mail sevice */
  85   if ((fp = fopen(PASSWD, "r")) == (FILE *) NULL)
  86         error("cannot open %s", PASSWD);
  87
  88   while (fgets(buf, BUFSIZ, fp) != (char *) NULL) {
  89         for (i = 0, s = buf; *s && *s != '\n'; s++)
  90                 if (*s == ':') i++;
  91         *s = '\0';
  92         if (i != 6) error("illegal '/etc/passwd' format: %s", buf);
  93
  94         /* Calendar file = ${HOME}/calendar */
  95         sprintf(calfile, "%s/%s", getstr(buf, 5), "calendar");
  96
  97         if ((access(calfile, R_OK) != 0) || (rflg && !newaccess(calfile)))
  98                 continue;
  99
 100         grep(calfile, getstr(buf, 0));
 101   }
 102
 103   fclose(fp);
 104 }
 105
 106 char *getstr(s, n)
 107 char *s;
 108 int n;
 109 {
 110 /* Returns the string value of the n-th field in the record (s) */
 111   int i;
 112   char *t;
 113   static char str[512];
 114
 115   for (i = 0; i < n && *s; s++)
 116         if (*s == ':') i++;             /* field separator */
 117   for (i = 0, t = str; *s && *s != ':' && i < 511; i++) *t++ = *s++;
 118   *t = '\0';
 119   return str;
 120 }
 121
 122 int newaccess(file)
 123 char *file;                     /* file name */
 124 {
 125 /* Check whether the file has been touched today. */
 126
 127   int r = 0;
 128   struct tm *tm;
 129   struct stat stbuf;
 130   time_t clk;
 131   char newdate[8], olddate[8];
 132
 133   time(&clk);
 134   tm = localtime(&clk);
 135   sprintf(newdate, "%02d%02d%02d", tm->tm_year, tm->tm_mon + 1, tm->tm_mday);
 136
 137   if (stat(file, &stbuf) == -1) error("cannot stat %s", file);
 138   tm = localtime(&stbuf.st_mtime);
 139   sprintf(olddate, "%02d%02d%02d", tm->tm_year, tm->tm_mon + 1, tm->tm_mday);
 140
 141   if (strcmp(newdate, olddate) != 0) {
 142         utime(file, NULL);      /* touch */
 143         r++;
 144   }
 145   return r;
 146 }
 147
 148 void grep(file, user)
 149 char *file, *user;
 150 {                               /* grep 'exp[]' [| mail user] */
 151   int i;
 152   char command[128];            /* mail command */
 153   FILE *ifp, *ofp;
 154
 155   if ((ifp = fopen(file, "r")) == (FILE *) NULL)
 156         error("cannot open %s", file);
 157   if (*user != '\0') {
 158         sprintf(command, "%s %s", mail, user);
 159         ofp = (FILE *) NULL;
 160   } else {
 161         ofp = stdout;
 162   }
 163
 164   while (fgets(buf, BUFSIZ, ifp) != (char *) NULL) {
 165         for (i = 0; i < nexp; i++) {
 166                 if (regexec(exp[i], buf, 1)) {
 167                         if ((ofp == (FILE *) NULL) &&
 168                                   (ofp = popen(command, "w")) == (FILE *) NULL)
 169                                 error("cannot popen %s", mail);
 170                         fputs(buf, ofp);
 171                         break;
 172                 }
 173         }
 174   }
 175
 176   fclose(ifp);
 177   if (ofp == stdout)
 178         fflush(ofp);
 179   else if (ofp != (FILE *) NULL)
 180         pclose(ofp);
 181 }
 182
 183 int date_exp()
 184 {
 185 /* Set compiled regular expressions into the exp[] array. */
 186   static int n[] = {2, 2, 2, 2, 2, 4, 3};
 187   int i, r, wday;
 188   time_t clk;
 189
 190   time(&clk);
 191   wday = localtime(&clk)->tm_wday;
 192   r = n[wday];
 193   if (r > MAX_EXP) error("too many date expressions", "");
 194   for (i = 0; i < r; i++) {
 195         exp[i] = regcomp(date_pat(clk));
 196         clk += 60 * 60 * 24L;   /* 24 hours */
 197   }
 198   return(r);
 199 }
 200
 201 char *date_pat(t)
 202 time_t t;
 203 {                               /* returns date expression for the time (t) */
 204   static char *month[] = {
 205          "[Jj]an", "[Ff]eb", "[Mm]ar", "[Aa]pr", "[Mm]ay", "[Jj]un",
 206           "[Jj]ul", "[Aa]ug", "[Ss]ep", "[Oo]ct", "[Nn]ov", "[Dd]ec"
 207   };
 208   static char str[512];
 209   struct tm *tm;
 210
 211   tm = localtime(&t);
 212   sprintf(str,
 213         "(^|[ \t(,;])(((%s[^ \t]*[ \t])|0*%d/|\\*/)(0*%d|\\*))([^0123456789]|$)",
 214         month[tm->tm_mon], tm->tm_mon + 1, tm->tm_mday);
 215
 216   return str;
 217 }
 218
 219 void regerror(s)
 220 const char *s;
 221 {                               /* regcomp() needs this */
 222   error("REGULAR EXPRESSION ERROR (%s)", (char *) s);
 223 }
 224
 225 void error(s, t)
 226 char *s, *t;
 227 {
 228   fprintf(stderr, "%s: ", cmd);
 229   fprintf(stderr, s, t);
 230   fprintf(stderr, "\n");
 231   exit(1);
 232 }