bin/ksh/mail.c

   1 /*      $OpenBSD: mail.c,v 1.24 2018/06/25 15:22:30 cheloha Exp $       */
   2
   3 /*
   4  * Mailbox checking code by Robert J. Gibson, adapted for PD ksh by
   5  * John R. MacMillan
   6  */
   7
   8 #include <sys/stat.h>
   9 #include <sys/time.h>
  10
  11 #include <string.h>
  12 #include <time.h>
  13
  14 #include "config.h"
  15 #include "sh.h"
  16
  17 #define MBMESSAGE       "you have mail in $_"
  18
  19 typedef struct mbox {
  20         struct mbox    *mb_next;        /* next mbox in list */
  21         char           *mb_path;        /* path to mail file */
  22         char           *mb_msg;         /* to announce arrival of new mail */
  23         time_t          mb_mtime;       /* mtime of mail file */
  24 } mbox_t;
  25
  26 /*
  27  * $MAILPATH is a linked list of mboxes.  $MAIL is a treated as a
  28  * special case of $MAILPATH, where the list has only one node.  The
  29  * same list is used for both since they are exclusive.
  30  */
  31
  32 static mbox_t   *mplist;
  33 static mbox_t   mbox;
  34 static struct   timespec mlastchkd;     /* when mail was last checked */
  35 static time_t   mailcheck_interval;
  36
  37 static void     munset(mbox_t *); /* free mlist and mval */
  38 static mbox_t * mballoc(char *, char *); /* allocate a new mbox */
  39 static void     mprintit(mbox_t *);
  40
  41 void
  42 mcheck(void)
  43 {
  44         mbox_t          *mbp;
  45         struct timespec  elapsed, now;
  46         struct tbl      *vp;
  47         struct stat      stbuf;
  48         static int       first = 1;
  49
  50         clock_gettime(CLOCK_MONOTONIC, &now);
  51         if (first) {
  52                 mlastchkd = now;
  53                 first = 0;
  54         }
  55         timespecsub(&now, &mlastchkd, &elapsed);
  56         if (elapsed.tv_sec >= mailcheck_interval) {
  57                 mlastchkd = now;
  58
  59                 if (mplist)
  60                         mbp = mplist;
  61                 else if ((vp = global("MAIL")) && (vp->flag & ISSET))
  62                         mbp = &mbox;
  63                 else
  64                         mbp = NULL;
  65
  66                 while (mbp) {
  67                         if (mbp->mb_path && stat(mbp->mb_path, &stbuf) == 0 &&
  68                             S_ISREG(stbuf.st_mode)) {
  69                                 if (stbuf.st_size &&
  70                                     mbp->mb_mtime != stbuf.st_mtime &&
  71                                     stbuf.st_atime <= stbuf.st_mtime)
  72                                         mprintit(mbp);
  73                                 mbp->mb_mtime = stbuf.st_mtime;
  74                         } else {
  75                                 /*
  76                                  * Some mail readers remove the mail
  77                                  * file if all mail is read.  If file
  78                                  * does not exist, assume this is the
  79                                  * case and set mtime to zero.
  80                                  */
  81                                 mbp->mb_mtime = 0;
  82                         }
  83                         mbp = mbp->mb_next;
  84                 }
  85         }
  86 }
  87
  88 void
  89 mcset(int64_t interval)
  90 {
  91         mailcheck_interval = interval;
  92 }
  93
  94 void
  95 mbset(char *p)
  96 {
  97         struct stat     stbuf;
  98
  99         afree(mbox.mb_msg, APERM);
 100         afree(mbox.mb_path, APERM);
 101         /* Save a copy to protect from export (which munges the string) */
 102         mbox.mb_path = str_save(p, APERM);
 103         mbox.mb_msg = NULL;
 104         if (p && stat(p, &stbuf) == 0 && S_ISREG(stbuf.st_mode))
 105                 mbox.mb_mtime = stbuf.st_mtime;
 106         else
 107                 mbox.mb_mtime = 0;
 108 }
 109
 110 void
 111 mpset(char *mptoparse)
 112 {
 113         mbox_t  *mbp;
 114         char    *mpath, *mmsg, *mval;
 115         char *p;
 116
 117         munset( mplist );
 118         mplist = NULL;
 119         mval = str_save(mptoparse, APERM);
 120         while (mval) {
 121                 mpath = mval;
 122                 if ((mval = strchr(mval, ':')) != NULL) {
 123                         *mval = '\0';
 124                         mval++;
 125                 }
 126                 /* POSIX/bourne-shell say file%message */
 127                 for (p = mpath; (mmsg = strchr(p, '%')); ) {
 128                         /* a literal percent? (POSIXism) */
 129                         if (mmsg[-1] == '\\') {
 130                                 /* use memmove() to avoid overlap problems */
 131                                 memmove(mmsg - 1, mmsg, strlen(mmsg) + 1);
 132                                 p = mmsg + 1;
 133                                 continue;
 134                         }
 135                         break;
 136                 }
 137                 /* at&t ksh says file?message */
 138                 if (!mmsg && !Flag(FPOSIX))
 139                         mmsg = strchr(mpath, '?');
 140                 if (mmsg) {
 141                         *mmsg = '\0';
 142                         mmsg++;
 143                 }
 144                 mbp = mballoc(mpath, mmsg);
 145                 mbp->mb_next = mplist;
 146                 mplist = mbp;
 147         }
 148 }
 149
 150 static void
 151 munset(mbox_t *mlist)
 152 {
 153         mbox_t  *mbp;
 154
 155         while (mlist != NULL) {
 156                 mbp = mlist;
 157                 mlist = mbp->mb_next;
 158                 if (!mlist)
 159                         afree(mbp->mb_path, APERM);
 160                 afree(mbp, APERM);
 161         }
 162 }
 163
 164 static mbox_t *
 165 mballoc(char *p, char *m)
 166 {
 167         struct stat     stbuf;
 168         mbox_t  *mbp;
 169
 170         mbp = alloc(sizeof(mbox_t), APERM);
 171         mbp->mb_next = NULL;
 172         mbp->mb_path = p;
 173         mbp->mb_msg = m;
 174         if (stat(mbp->mb_path, &stbuf) == 0 && S_ISREG(stbuf.st_mode))
 175                 mbp->mb_mtime = stbuf.st_mtime;
 176         else
 177                 mbp->mb_mtime = 0;
 178         return(mbp);
 179 }
 180
 181 static void
 182 mprintit(mbox_t *mbp)
 183 {
 184         struct tbl      *vp;
 185
 186 #if 0
 187         /*
 188          * I doubt this $_ overloading is bad in /bin/sh mode.  Anyhow, we
 189          * crash as the code looks now if we do not set vp.  Now, this is
 190          * easy to fix too, but I'd like to see what POSIX says before doing
 191          * a change like that.
 192          */
 193         if (!Flag(FSH))
 194 #endif
 195                 /* Ignore setstr errors here (arbitrary) */
 196                 setstr((vp = local("_", false)), mbp->mb_path, KSH_RETURN_ERROR);
 197
 198         shellf("%s\n", substitute(mbp->mb_msg ? mbp->mb_msg : MBMESSAGE, 0));
 199
 200         unset(vp, 0);
 201 }