source: popexec.c @ 0b20de4

release-1.8release-1.9
Last change on this file since 0b20de4 was 47e0a6a, checked in by David Benjamin <davidben@mit.edu>, 11 years ago
Punt a number of g_new NULL checks, various minor cleanups No real need to check g_new's return value as it always succeeds. (Or destroys the universe^Wprocess in embarrassment.) Also make owl_global manage the lifetime of the kill buffer since it's part of owl_global now. And replace a g_new/strncpy with a g_strndup. It's shorter.
  • 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  if (owl_global_get_popwin(&g) || owl_global_get_viewwin(&g)) {
20    owl_function_error("Popwin already in use.");
21    return NULL;
22  }
23
24  pe = g_new(owl_popexec, 1);
25  pe->winactive=0;
26  pe->pid=0;
27  pe->refcount=0;
28
29  pw = owl_popwin_new();
30  owl_global_set_popwin(&g, pw);
31  owl_popwin_up(pw);
32  pe->vwin = v = owl_viewwin_new_text(owl_popwin_get_content(pw), "");
33  owl_global_set_viewwin(&g, v);
34  owl_viewwin_set_onclose_hook(v, owl_popexec_viewwin_onclose, pe);
35
36  owl_global_push_context(&g, OWL_CTX_POPLESS, v, "popless", NULL);
37  pe->refcount++;
38
39  if (0 != pipe(pipefds)) {
40    owl_function_error("owl_function_popless_exec: pipe failed\n");
41    return NULL;
42  }
43  parent_read_fd = pipefds[0];
44  child_write_fd = pipefds[1];
45  pid = fork();
46  if (pid == -1) {
47    close(pipefds[0]);
48    close(pipefds[1]);
49    owl_function_error("owl_function_popless_exec: fork failed\n");
50    return NULL;
51  } else if (pid != 0) {
52    close(child_write_fd);
53    /* still in owl */
54    pe->pid=pid;
55    pe->winactive=1;
56    pe->dispatch = owl_select_add_io_dispatch(parent_read_fd, OWL_IO_READ|OWL_IO_EXCEPT, &owl_popexec_inputhandler, &owl_popexec_delete_dispatch, pe);
57    pe->refcount++;
58  } else {
59    /* in the child process */
60    int i;
61    int fdlimit = sysconf(_SC_OPEN_MAX);
62
63    for (i=0; i<fdlimit; i++) {
64      if (i!=child_write_fd) close(i);
65    }
66    dup2(child_write_fd, 1 /*stdout*/);
67    dup2(child_write_fd, 2 /*stderr*/);
68    close(child_write_fd);
69
70    execl("/bin/sh", "sh", "-c", command, (const char *)NULL);
71    _exit(127);
72  }
73
74  return pe;
75}
76
77void owl_popexec_inputhandler(const owl_io_dispatch *d, void *data)
78{
79  owl_popexec *pe = data;
80  int navail, bread, rv_navail;
81  char *buf;
82  int status;
83
84  if (!pe) return;
85
86  /* If pe->winactive is 0 then the vwin has closed.
87   * If pe->pid is 0 then the child has already been reaped.
88   * if d->fd is -1 then the fd has been closed out.
89   * Under these cases we want to get to a state where:
90   *   - data read until end if child running
91   *   - child reaped
92   *   - fd closed
93   *   - callback removed
94   */
95
96  /* the viewwin has closed */
97  if (!pe->pid && !pe->winactive) {
98    owl_select_remove_io_dispatch(d);
99    pe->dispatch = NULL;
100    return;
101  }
102
103  if (0 != (rv_navail = ioctl(d->fd, FIONREAD, &navail))) {
104    owl_function_debugmsg("ioctl error");
105  }
106
107  /* check to see if the child has ended gracefully and no more data is
108   * ready to be read... */
109  if (navail==0 && pe->pid>0 && waitpid(pe->pid, &status, WNOHANG) > 0) {
110    owl_function_debugmsg("waitpid got child status: <%d>\n", status);
111    pe->pid = 0;
112    if (pe->winactive) { 
113      owl_viewwin_append_text(pe->vwin, "\n");
114    }
115    owl_select_remove_io_dispatch(d);
116    pe->dispatch = NULL;
117    return;
118  }
119
120  if (d->fd<0 || !pe->pid || !pe->winactive || rv_navail) {
121    owl_function_error("popexec should not have reached this point");
122    return;
123  }
124
125  if (navail<=0) return;
126  if (navail>1024) { navail = 1024; }
127  buf = g_new(char, navail+1);
128  owl_function_debugmsg("about to read %d", navail);
129  bread = read(d->fd, buf, navail);
130  if (bread<0) {
131    perror("read");
132    owl_function_debugmsg("read error");
133  }
134  if (buf[navail-1] != '\0') {
135    buf[navail] = '\0';
136  }
137  owl_function_debugmsg("got data:  <%s>", buf);
138  if (pe->winactive) {
139    owl_viewwin_append_text(pe->vwin, buf);
140  }
141  g_free(buf);
142 
143}
144
145void owl_popexec_delete_dispatch(const owl_io_dispatch *d)
146{
147  owl_popexec *pe = d->data;
148  close(d->fd);
149  owl_popexec_unref(pe);
150}
151
152void owl_popexec_viewwin_onclose(owl_viewwin *vwin, void *data)
153{
154  owl_popexec *pe = data;
155  int status, rv;
156
157  pe->winactive = 0;
158  if (pe->dispatch) {
159    owl_select_remove_io_dispatch(pe->dispatch);
160    pe->dispatch = NULL;
161  }
162  if (pe->pid) {
163    /* TODO: we should handle the case where SIGTERM isn't good enough */
164    rv = kill(pe->pid, SIGTERM);
165    owl_function_debugmsg("kill of pid %d returned %d", pe->pid, rv);
166    rv = waitpid(pe->pid, &status, 0);
167    owl_function_debugmsg("waidpid returned %d, status %d", rv, status);
168    pe->pid = 0;
169  }
170  owl_function_debugmsg("unref of %p from onclose", pe);
171  owl_popexec_unref(pe);
172}
173
174void owl_popexec_unref(owl_popexec *pe)
175{
176  owl_function_debugmsg("unref of %p was %d", pe, pe->refcount);
177  pe->refcount--;
178  if (pe->refcount<=0) {
179    owl_function_debugmsg("doing free of %p", pe);
180    g_free(pe);
181  }
182}
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