cmd.c

   1 #include <fcntl.h>
   2 #include <poll.h>
   3 #include <signal.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <unistd.h>
   8 #include <sys/wait.h>
   9 #include "vi.h"
  10
  11 static int cmd_make(char **argv, int *ifd, int *ofd)
  12 {
  13         int pid;
  14         int pipefds0[2];
  15         int pipefds1[2];
  16         if (ifd)
  17                 pipe(pipefds0);
  18         if (ofd)
  19                 pipe(pipefds1);
  20         if (!(pid = fork())) {
  21                 if (ifd) {              /* setting up stdin */
  22                         close(0);
  23                         dup(pipefds0[0]);
  24                         close(pipefds0[1]);
  25                         close(pipefds0[0]);
  26                 }
  27                 if (ofd) {              /* setting up stdout */
  28                         close(1);
  29                         dup(pipefds1[1]);
  30                         close(pipefds1[0]);
  31                         close(pipefds1[1]);
  32                 }
  33                 execvp(argv[0], argv);
  34                 exit(1);
  35         }
  36         if (ifd)
  37                 close(pipefds0[0]);
  38         if (ofd)
  39                 close(pipefds1[1]);
  40         if (pid < 0) {
  41                 if (ifd)
  42                         close(pipefds0[1]);
  43                 if (ofd)
  44                         close(pipefds1[0]);
  45                 return -1;
  46         }
  47         if (ifd)
  48                 *ifd = pipefds0[1];
  49         if (ofd)
  50                 *ofd = pipefds1[0];
  51         return pid;
  52 }
  53
  54 /* execute a command; process input if iproc and process output if oproc */
  55 char *cmd_pipe(char *cmd, char *ibuf, int iproc, int oproc)
  56 {
  57         char *argv[] = {"/bin/sh", "-c", cmd, NULL};
  58         struct pollfd fds[3];
  59         struct sbuf *sb = NULL;
  60         char buf[512];
  61         int ifd = -1, ofd = -1;
  62         int slen = iproc ? strlen(ibuf) : 0;
  63         int nw = 0;
  64         int pid = cmd_make(argv, iproc ? &ifd : NULL, oproc ? &ofd : NULL);
  65         if (pid <= 0)
  66                 return NULL;
  67         if (oproc)
  68                 sb = sbuf_make();
  69         if (!iproc) {
  70                 signal(SIGINT, SIG_IGN);
  71                 term_done();
  72         }
  73         fcntl(ifd, F_SETFL, fcntl(ifd, F_GETFL, 0) | O_NONBLOCK);
  74         fds[0].fd = ofd;
  75         fds[0].events = POLLIN;
  76         fds[1].fd = ifd;
  77         fds[1].events = POLLOUT;
  78         fds[2].fd = iproc ? 0 : -1;
  79         fds[2].events = POLLIN;
  80         while ((fds[0].fd >= 0 || fds[1].fd >= 0) && poll(fds, 3, 200) >= 0) {
  81                 if (fds[0].revents & POLLIN) {
  82                         int ret = read(fds[0].fd, buf, sizeof(buf));
  83                         if (ret > 0)
  84                                 sbuf_mem(sb, buf, ret);
  85                         if (ret < 0)
  86                                 close(fds[0].fd);
  87                 } else if (fds[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
  88                         fds[0].fd = -1;
  89                 }
  90                 if (fds[1].revents & POLLOUT) {
  91                         int ret = write(fds[1].fd, ibuf + nw, slen - nw);
  92                         if (ret > 0)
  93                                 nw += ret;
  94                         if (ret <= 0 || nw == slen)
  95                                 close(fds[1].fd);
  96                 } else if (fds[1].revents & (POLLERR | POLLHUP | POLLNVAL)) {
  97                         fds[1].fd = -1;
  98                 }
  99                 if (fds[2].revents & POLLIN) {
 100                         int ret = read(fds[2].fd, buf, sizeof(buf));
 101                         int i;
 102                         for (i = 0; i < ret; i++)
 103                                 if ((unsigned char) buf[i] == TK_CTL('c'))
 104                                         kill(pid, SIGINT);
 105                 } else if (fds[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
 106                         fds[2].fd = -1;
 107                 }
 108         }
 109         close(ifd);
 110         close(ofd);
 111         waitpid(pid, NULL, 0);
 112         if (!iproc) {
 113                 term_init();
 114                 signal(SIGINT, SIG_DFL);
 115         }
 116         if (oproc)
 117                 return sbuf_done(sb);
 118         return NULL;
 119 }
 120
 121 int cmd_exec(char *cmd)
 122 {
 123         cmd_pipe(cmd, NULL, 0, 0);
 124         return 0;
 125 }