1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
/* Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
*/
#include <stdio.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/resource.h>
#define import_kernel
#define import_knames
#define import_error
#define import_spp
#include <iraf.h>
#ifdef LINUX
#define USE_SIGACTION
#endif
static int lastsig;
extern int pr_onint();
#ifdef SYSV
#define vfork fork
#else
# ifdef sun
# include <vfork.h>
# endif
#endif
extern void pr_enter (int pid, int inchan, int outchan);
extern int pr_wait (int pid);
/* ZOSCMD -- Send a (machine dependent) command to the host operating
* system. If nonnull stdout or stderr filenames are given, try to spool
* the output in these files.
*/
int
ZOSCMD (
PKCHAR *oscmd,
PKCHAR *stdin_file,
PKCHAR *stdout_file,
PKCHAR *stderr_file,
XINT *status
)
{
char *shell, *sh = "/bin/sh";
char *sin, *sout, *serr, *cmd;
struct rlimit rlim;
int maxfd, fd, pid;
char *getenv();
#ifdef USE_SIGACTION
struct sigaction oldact;
#else
SIGFUNC old_sigint;
#endif
extern int _u_fmode();
cmd = (char *)oscmd;
sin = (char *)stdin_file;
sout = (char *)stdout_file;
serr = (char *)stderr_file;
/* The Bourne shell SH is used if the first character of the cmd
* is '!' or if the user does not have SHELL defined in their
* environment.
*/
if (*cmd == '!') {
shell = sh;
cmd++;
} else if ((shell = getenv ("SHELL")) == NULL)
shell = sh;
#ifdef USE_SIGACTION
sigaction (SIGINT, NULL, &oldact);
#else
old_sigint = (SIGFUNC) signal (SIGINT, SIG_IGN);
#endif
/* Vfork is faster if we can use it.
*/
if (*sin == EOS && *sout == EOS && *serr == EOS) {
while ((pid = vfork()) == ERR)
sleep (2);
} else {
while ((pid = fork()) == ERR)
sleep (2);
}
if (pid == 0) {
/* Child.
*/
/* Run the system call. Let child inherit the parents standard
* input unless redirected by nonnull stdin_file. Set standard
* output and error output streams if filenames given, else write
* to same files (i.e., terminal) as parent.
*/
if (*sin != EOS) { /* stdin */
fd = open (sin, 0);
if (fd == ERR) {
fprintf (stderr, "cannot open `%s'\n", sin);
_exit (1);
}
close (0); dup (fd); close (fd);
}
if (*sout != EOS) { /* stdout */
fd = creat (sout, _u_fmode(FILE_MODEBITS));
if (fd == ERR)
fprintf (stderr, "cannot create `%s'\n", sout);
else {
close (1); dup (fd); close (fd);
}
}
if (*serr != EOS) { /* stderr */
/* If stdout and stderr are to go to the same file,
* dup stdout file descriptor as stderr.
*/
if (strcmp (sout, serr) == 0) {
close (2); dup (1);
} else {
fd = creat (serr, _u_fmode(FILE_MODEBITS));
if (fd == ERR)
fprintf (stderr, "cannot create `%s'\n", serr);
else {
close (2); dup (fd); close (fd);
}
}
}
if (getrlimit (RLIMIT_NOFILE, &rlim))
maxfd = MAXOFILES;
else
maxfd = rlim.rlim_cur;
/* Arrange for the local file descriptors of the parent to be closed
* in the child if the exec succeeds. If this is not done the child
* may run out of file descriptors.
*/
for (fd=3; fd < min(MAXOFILES,maxfd); fd++)
fcntl (fd, F_SETFD, 1);
/* Spawn a shell to execute the command.
*/
/* Setting old_sigint here doesn't make sense if we will be
* execl-ing a different process. Use SIG_DFL instead.
signal (SIGINT, old_sigint);
*/
signal (SIGINT, SIG_DFL);
execl (shell, shell, "-c", cmd, (char *) 0);
/* NOTREACHED (unless execl fails) */
_exit (1);
}
/* Parent: wait for child to finish up. Parent process should ignore
* interrupts; OS process will handle interrupts and return at the
* proper time. The parent is out of the picture while the OS process
* is running (except for the pr_onint interrupt handler, below).
*/
pr_enter (pid, 0, 0);
lastsig = 0;
#ifndef SYSV
/* This doesn't appear to work on SysV systems, I suspect that wait()
* is not being reentered after the signal handler below. This could
* probably be fixed by modifying the signal handling but I am not
* sure the parent needs to intercept errors in any case, so lets
* try really ignoring errors in the parent instead, on SYSV systems.
*/
if (old_sigint != SIG_IGN)
signal (SIGINT, (SIGFUNC) pr_onint);
#endif
*status = pr_wait (pid);
/* If the OS command was interrupted, ignore its exit status and return
* the interrupt exception code to the calling program. Do not return
* the interrupt code unless an interrupt occurs.
*/
if (*status == SYS_XINT)
*status = 1;
if (lastsig == SIGINT)
*status = SYS_XINT;
#ifdef USE_SIGACTION
sigaction (SIGINT, &oldact, NULL);
#else
signal (SIGINT, old_sigint);
#endif
return (XOK);
}
/* PR_ONINT -- Special interrupt handler for ZOSCMD. If the OS command is
* interrupted, post a flag to indicate this to ZOSCMD when the pr_wait()
* returns.
*/
int
pr_onint (
int usig, /* SIGINT, SIGFPE, etc. */
int *hwcode, /* not used */
int *scp /* not used */
)
{
lastsig = usig;
/* return to wait() */
return (XOK);
}
|
