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 #define NHEAD                   (1 << 4)
  14
  15 static char buf[BUFSIZE];
  16 static int cur;
  17 static int len;
  18
  19 static int read_line(char *dst, int size)
  20 {
  21         int nw = 0;
  22         while (1) {
  23                 int cur_len = MIN(len - cur, size - nw - 1);
  24                 char *nl = memchr(buf + cur, '\n', cur_len);
  25                 int nr = nl ? nl - buf - cur + 1 : cur_len;
  26                 if (nr) {
  27                         memcpy(dst + nw, buf + cur, nr);
  28                         nw += nr;
  29                         cur += nr;
  30                         dst[nw] = '\0';
  31                 }
  32                 if (nl || nw == size - 1)
  33                         return nw;
  34                 cur = 0;
  35                 if ((len = read(STDIN_FILENO, buf, BUFSIZE)) <= 0)
  36                         return -1;
  37         }
  38         return nw;
  39 }
  40
  41 static void till_eol(char *s)
  42 {
  43         char *r = s;
  44         while (*s && *s != '\r' && *s != '\n')
  45                 s++;
  46         write(1, r, s - r);
  47         write(1, "\n", 1);
  48 }
  49
  50 static char *cut_int(char *dst, char *s)
  51 {
  52         while (isspace(*s))
  53                 s++;
  54         while (isdigit(*s))
  55                 *dst++ = *s++;
  56         *dst = '\0';
  57         return s;
  58 }
  59
  60 static void cmd_page(struct mbox *mbox, char *args)
  61 {
  62         struct mail *mail;
  63         pid_t pid;
  64         int fds[2];
  65         char num[MAXLINE];
  66         int n = mbox->c;
  67         args = cut_int(num, args);
  68         if (isdigit(*num))
  69                 n = atoi(num);
  70         if (n < 0 && n >= mbox->n)
  71                 return;
  72         mail = &mbox->mails[n];
  73         mbox->c = n;
  74         pipe(fds);
  75         if (!(pid = fork())) {
  76                 char *args[] = {PAGER, NULL};
  77                 close(fds[1]);
  78                 dup2(fds[0], STDIN_FILENO);
  79                 execvp(PAGER, args);
  80                 exit(1);
  81         }
  82         close(fds[0]);
  83         write(fds[1], mail->head, mail->len);
  84         close(fds[1]);
  85         waitpid(pid, NULL, 0);
  86 }
  87
  88 static char *cut_cmd(char *dst, char *s)
  89 {
  90         while (isalpha(*s)) {
  91                 *dst++ = *s++;
  92         }
  93         *dst = '\0';
  94         return s;
  95 }
  96
  97 static char *put_int(char *s, int n, int w)
  98 {
  99         int i;
 100         for (i = 0; i < w; i++) {
 101                 s[w - i - 1] = n || !i ? '0' + n % 10 : ' ';
 102                 n = n / 10;
 103         }
 104         return s + w;
 105 }
 106
 107 static void cmd_head(struct mbox *mbox, char *args)
 108 {
 109         int i;
 110         int beg = mbox->c / NHEAD * NHEAD;
 111         int end = MIN(beg + NHEAD, mbox->n);
 112         if (!mbox->n)
 113                 return;
 114         for (i = beg; i < end; i++) {
 115                 char fmt[16] = {0};
 116                 char *s = fmt;
 117                 *s++ = i == mbox->c ? '>' : ' ';
 118                 s = put_int(s, i, 5);
 119                 *s++ = ' ';
 120                 *s++ = ' ';
 121                 write(STDOUT_FILENO, fmt, strlen(fmt));
 122                 if (mbox->mails[i].subject)
 123                         till_eol(mbox->mails[i].subject + 9);
 124         }
 125 }
 126
 127 static void loop(struct mbox *mbox)
 128 {
 129         char line[MAXLINE];
 130         char cmd[MAXLINE];
 131         while (read_line(line, sizeof(line)) > 0) {
 132                 char *args = cut_cmd(cmd, line);
 133                 int len = strlen(cmd);
 134                 if (!strncmp("header", cmd, len))
 135                         cmd_head(mbox, args);
 136                 if (!strncmp("page", cmd, len))
 137                         cmd_page(mbox, args);
 138                 if (!strncmp("quit", cmd, len))
 139                         return;
 140                 if (!strncmp("x", cmd, len) || !strncmp("exit", cmd, len))
 141                         return;
 142         }
 143 }
 144
 145 int main(int argc, char *argv[])
 146 {
 147         int i = 0;
 148         struct mbox *mbox;
 149         char *filename = NULL;
 150         while (++i < argc)
 151                 if (!strcmp("-f", argv[i]))
 152                         filename = argv[++i];
 153         if (filename) {
 154                 mbox = mbox_alloc(filename);
 155                 loop(mbox);
 156                 mbox_free(mbox);
 157         }
 158         return 0;
 159 }