source: popexec.c @ 82fbdf0

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Last change on this file since 82fbdf0 was 0e5afa2, checked in by Anders Kaseorg <andersk@mit.edu>, 12 years ago
Use pid_t type for pids. Signed-off-by: Anders Kaseorg <andersk@mit.edu>
  • Property mode set to 100644
File size: 4.6 KB
Line 
1#include "owl.h"
2#ifdef HAVE_SYS_IOCTL_H
3#include <sys/ioctl.h>
4#endif
5#ifdef HAVE_SYS_FILIO_H
6#include <sys/filio.h>
7#endif
8#include <sys/wait.h>
9
10/* starts up popexec in a new viewwin */
11owl_popexec *owl_popexec_new(const char *command)
12{
13  owl_popexec *pe;
14  owl_popwin *pw;
15  owl_viewwin *v;
16  int pipefds[2], child_write_fd, parent_read_fd;
17  pid_t pid;
18
19  pe = owl_malloc(sizeof(owl_popexec));
20  if (!pe) return NULL;
21  pe->winactive=0;
22  pe->pid=0;
23  pe->refcount=0;
24
25  pw=owl_global_get_popwin(&g);
26  pe->vwin=v=owl_global_get_viewwin(&g);
27
28  owl_popwin_up(pw);
29  owl_viewwin_init_text(v, owl_popwin_get_curswin(pw),
30                        owl_popwin_get_lines(pw), owl_popwin_get_cols(pw),
31                        "");
32  owl_popwin_refresh(pw);
33  owl_viewwin_redisplay(v, 0);
34  owl_global_set_needrefresh(&g);
35  owl_viewwin_set_onclose_hook(v, owl_popexec_viewwin_onclose, pe);
36  pe->refcount++;
37
38  if (0 != pipe(pipefds)) {
39    owl_function_error("owl_function_popless_exec: pipe failed\n");
40    return NULL;
41  }
42  parent_read_fd = pipefds[0];
43  child_write_fd = pipefds[1];
44  pid = fork();
45  if (pid == -1) {
46    close(pipefds[0]);
47    close(pipefds[1]);
48    owl_function_error("owl_function_popless_exec: fork failed\n");
49    return NULL;
50  } else if (pid != 0) {
51    close(child_write_fd);
52    /* still in owl */
53    pe->pid=pid;
54    pe->winactive=1;
55    pe->dispatch.fd = parent_read_fd;
56    pe->dispatch.cfunc = owl_popexec_inputhandler;
57    pe->dispatch.destroy = owl_popexec_free_dispatch;
58    pe->dispatch.data = pe;
59    owl_select_add_dispatch(&pe->dispatch);
60    pe->refcount++;
61  } else {
62    /* in the child process */
63    int i;
64    int fdlimit = sysconf(_SC_OPEN_MAX);
65
66    for (i=0; i<fdlimit; i++) {
67      if (i!=child_write_fd) close(i);
68    }
69    dup2(child_write_fd, 1 /*stdout*/);
70    dup2(child_write_fd, 2 /*stderr*/);
71    close(child_write_fd);
72
73    execl("/bin/sh", "sh", "-c", command, (const char *)NULL);
74    _exit(127);
75  }
76
77  return pe;
78}
79
80void owl_popexec_inputhandler(owl_dispatch *d)
81{
82  owl_popexec *pe = d->data;
83  int navail, bread, rv_navail;
84  char *buf;
85  int status;
86
87  if (!pe) return;
88
89  /* If pe->winactive is 0 then the vwin has closed.
90   * If pe->pid is 0 then the child has already been reaped.
91   * if d->fd is -1 then the fd has been closed out.
92   * Under these cases we want to get to a state where:
93   *   - data read until end if child running
94   *   - child reaped
95   *   - fd closed
96   *   - callback removed
97   */
98
99  /* the viewwin has closed */
100  if (!pe->pid && !pe->winactive) {
101    owl_select_remove_dispatch(d->fd);
102    return;
103  }
104
105  if (0 != (rv_navail = ioctl(d->fd, FIONREAD, &navail))) {
106    owl_function_debugmsg("ioctl error");
107  }
108
109  /* check to see if the child has ended gracefully and no more data is
110   * ready to be read... */
111  if (navail==0 && pe->pid>0 && waitpid(pe->pid, &status, WNOHANG) > 0) {
112    owl_function_debugmsg("waitpid got child status: <%d>\n", status);
113    pe->pid = 0;
114    if (pe->winactive) { 
115      owl_viewwin_append_text(pe->vwin, "\n");
116      owl_viewwin_redisplay(pe->vwin, 1);
117    }
118    owl_select_remove_dispatch(d->fd);
119    return;
120  }
121
122  if (d->fd<0 || !pe->pid || !pe->winactive || rv_navail) {
123    owl_function_error("popexec should not have reached this point");
124    return;
125  }
126
127  if (navail<=0) return;
128  if (navail>1024) { navail = 1024; }
129  buf = owl_malloc(navail+1);
130  owl_function_debugmsg("about to read %d", navail);
131  bread = read(d->fd, buf, navail);
132  if (bread<0) {
133    perror("read");
134    owl_function_debugmsg("read error");
135  }
136  if (buf[navail-1] != '\0') {
137    buf[navail] = '\0';
138  }
139  owl_function_debugmsg("got data:  <%s>", buf);
140  if (pe->winactive) {
141    owl_viewwin_append_text(pe->vwin, buf);
142    owl_viewwin_redisplay(pe->vwin, 1);
143  }
144  owl_free(buf);
145 
146}
147
148void owl_popexec_free_dispatch(owl_dispatch *d)
149{
150  owl_popexec *pe = d->data;
151  close(d->fd);
152  owl_popexec_unref(pe);
153}
154
155void owl_popexec_viewwin_onclose(owl_viewwin *vwin, void *data)
156{
157  owl_popexec *pe = data;
158  int status, rv;
159
160  pe->winactive = 0;
161  if (pe->dispatch.fd>0) {
162    owl_select_remove_dispatch(pe->dispatch.fd);
163  }
164  if (pe->pid) {
165    /* TODO: we should handle the case where SIGTERM isn't good enough */
166    rv = kill(pe->pid, SIGTERM);
167    owl_function_debugmsg("kill of pid %d returned %d", pe->pid, rv);
168    rv = waitpid(pe->pid, &status, 0);
169    owl_function_debugmsg("waidpid returned %d, status %d", rv, status);
170    pe->pid = 0;
171  }
172  owl_function_debugmsg("unref of %p from onclose", pe);
173  owl_popexec_unref(pe);
174}
175
176void owl_popexec_unref(owl_popexec *pe)
177{
178  owl_function_debugmsg("unref of %p was %d", pe, pe->refcount);
179  pe->refcount--;
180  if (pe->refcount<=0) {
181    owl_function_debugmsg("doing free of %p", pe);
182    owl_free(pe);
183  }
184}
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