cmd.c

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