mailx.c

   1 #include <ctype.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5 #include <sys/types.h>
   6 #include <sys/wait.h>
   7 #include "mbox.h"
   8
   9 #define MIN(a, b)               ((a) < (b) ? (a) : (b))
  10 #define MAXLINE                 (1 << 7)
  11 #define BUFSIZE                 (1 << 12)
  12 #define PAGER                   "pgmail"
  13
  14 static char buf[BUFSIZE];
  15 static int cur;
  16 static int len;
  17
  18 static int read_line(char *dst, int size)
  19 {
  20         int nw = 0;
  21         while (1) {
  22                 int cur_len = MIN(len - cur, size - nw - 1);
  23                 char *nl = memchr(buf + cur, '\n', cur_len);
  24                 int nr = nl ? nl - buf - cur + 1 : cur_len;
  25                 if (nr) {
  26                         memcpy(dst + nw, buf + cur, nr);
  27                         nw += nr;
  28                         cur += nr;
  29                         dst[nw] = '\0';
  30                 }
  31                 if (nl || nw == size - 1)
  32                         return nw;
  33                 cur = 0;
  34                 if ((len = read(STDIN_FILENO, buf, BUFSIZE)) <= 0)
  35                         return -1;
  36         }
  37         return nw;
  38 }
  39
  40 static void till_eol(char *s)
  41 {
  42         char *r = s;
  43         while (*s && *s != '\r' && *s != '\n')
  44                 s++;
  45         write(1, r, s - r);
  46         write(1, "\n", 1);
  47 }
  48
  49 static char *cut_int(char *dst, char *s)
  50 {
  51         while (isspace(*s))
  52                 s++;
  53         while (isdigit(*s))
  54                 *dst++ = *s++;
  55         *dst = '\0';
  56         return s;
  57 }
  58
  59 static void cmd_page(struct mbox *mbox, char *args)
  60 {
  61         struct mail *mail;
  62         pid_t pid;
  63         int fds[2];
  64         char num[MAXLINE];
  65         int n = mbox->c;
  66         args = cut_int(num, args);
  67         if (isdigit(*num))
  68                 n = atoi(num);
  69         if (n < 0 && n >= mbox->n)
  70                 return;
  71         mail = &mbox->mails[n];
  72         mbox->c = n;
  73         pipe(fds);
  74         if (!(pid = fork())) {
  75                 char *args[] = {PAGER, NULL};
  76                 close(fds[1]);
  77                 dup2(fds[0], STDIN_FILENO);
  78                 execvp(PAGER, args);
  79                 exit(1);
  80         }
  81         close(fds[0]);
  82         write(fds[1], mail->head, mail->len);
  83         close(fds[1]);
  84         waitpid(pid, NULL, 0);
  85 }
  86
  87 static char *cut_cmd(char *dst, char *s)
  88 {
  89         while (isalpha(*s)) {
  90                 *dst++ = *s++;
  91         }
  92         *dst = '\0';
  93         return s;
  94 }
  95
  96 static void cmd_head(struct mbox *mbox, char *args)
  97 {
  98         int i;
  99         int n = MIN(mbox->n, 10);
 100         for (i = 0; i < n; i++)
 101                 if (mbox->mails[i].subject)
 102                         till_eol(mbox->mails[i].subject);
 103 }
 104
 105 static void loop(struct mbox *mbox)
 106 {
 107         char line[MAXLINE];
 108         char cmd[MAXLINE];
 109         while (read_line(line, sizeof(line)) > 0) {
 110                 char *args = cut_cmd(cmd, line);
 111                 int len = strlen(cmd);
 112                 if (!strncmp("header", cmd, len))
 113                         cmd_head(mbox, args);
 114                 if (!strncmp("page", cmd, len))
 115                         cmd_page(mbox, args);
 116                 if (!strncmp("quit", cmd, len))
 117                         return;
 118                 if (!strncmp("x", cmd, len) || !strncmp("exit", cmd, len))
 119                         return;
 120         }
 121 }
 122
 123 int main(int argc, char *argv[])
 124 {
 125         int i = 0;
 126         struct mbox *mbox;
 127         char *filename = NULL;
 128         while (++i < argc)
 129                 if (!strcmp("-f", argv[i]))
 130                         filename = argv[++i];
 131         if (filename) {
 132                 mbox = mbox_alloc(filename);
 133                 loop(mbox);
 134                 mbox_free(mbox);
 135         }
 136         return 0;
 137 }