cmd.c

   1 #include <poll.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <sys/wait.h>
   7 #include "vi.h"
   8
   9 static int cmd_make(char **argv, int *ifd, int *ofd)
  10 {
  11         int pid;
  12         int pipefds0[2];
  13         int pipefds1[2];
  14         if (ifd)
  15                 pipe(pipefds0);
  16         if (ofd)
  17                 pipe(pipefds1);
  18         if (!(pid = fork())) {
  19                 if (ifd) {              /* setting up stdin */
  20                         close(0);
  21                         dup(pipefds0[0]);
  22                         close(pipefds0[1]);
  23                         close(pipefds0[0]);
  24                 }
  25                 if (ofd) {              /* setting up stdout */
  26                         close(1);
  27                         dup(pipefds1[1]);
  28                         close(pipefds1[0]);
  29                         close(pipefds1[1]);
  30                 }
  31                 execvp(argv[0], argv);
  32                 exit(1);
  33         }
  34         if (ifd)
  35                 close(pipefds0[0]);
  36         if (ofd)
  37                 close(pipefds1[1]);
  38         if (pid < 0) {
  39                 if (ifd)
  40                         close(pipefds0[1]);
  41                 if (ofd)
  42                         close(pipefds1[0]);
  43                 return -1;
  44         }
  45         if (ifd)
  46                 *ifd = pipefds0[1];
  47         if (ofd)
  48                 *ofd = pipefds1[0];
  49         return pid;
  50 }
  51
  52 char *cmd_pipe(char *cmd, char *s)
  53 {
  54         char *argv[] = {"/bin/sh", "-c", cmd, NULL};
  55         struct pollfd fds[2];
  56         struct sbuf *sb;
  57         char buf[512];
  58         int ifd = 0, ofd = 0;
  59         int slen = strlen(s);
  60         int nw = 0;
  61         int pid = cmd_make(argv, &ifd, &ofd);
  62         if (pid <= 0)
  63                 return NULL;
  64         sb = sbuf_make();
  65         fds[0].fd = ofd;
  66         fds[0].events = POLLIN;
  67         fds[1].fd = ifd;
  68         fds[1].events = POLLOUT;
  69         while ((fds[0].fd >= 0 || fds[1].fd >= 0) && poll(fds, 3, 200) >= 0) {
  70                 if (fds[0].revents & POLLIN) {
  71                         int ret = read(fds[0].fd, buf, sizeof(buf));
  72                         if (ret > 0)
  73                                 sbuf_mem(sb, buf, ret);
  74                         if (ret < 0)
  75                                 close(fds[0].fd);
  76                 } else if (fds[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
  77                         fds[0].fd = -1;
  78                 }
  79                 if (fds[1].revents & POLLOUT) {
  80                         int ret = write(fds[1].fd, s + nw, slen - nw);
  81                         if (ret > 0)
  82                                 nw += ret;
  83                         if (ret <= 0 || nw == slen)
  84                                 close(fds[1].fd);
  85                 } else if (fds[1].revents & (POLLERR | POLLHUP | POLLNVAL)) {
  86                         fds[1].fd = -1;
  87                 }
  88         }
  89         waitpid(pid, NULL, 0);
  90         return sbuf_done(sb);
  91 }