aboutsummaryrefslogtreecommitdiffstats
path: root/ex/ex_shell.c
blob: 7b483fd4e14cca25991552ab1daf3b516ee4322e (plain) (blame)
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
220
221
222
223
/*-
 * Copyright (c) 1992, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *	Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#include <sys/queue.h>
#include <sys/time.h>
#include <sys/wait.h>

#include <bitstring.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "../common/common.h"

static const char *sigmsg(int);

/*
 * ex_shell -- :sh[ell]
 *	Invoke the program named in the SHELL environment variable
 *	with the argument -i.
 *
 * PUBLIC: int ex_shell(SCR *, EXCMD *);
 */
int
ex_shell(SCR *sp, EXCMD *cmdp)
{
	int rval;
	char *buf;

	/* We'll need a shell. */
	if (opts_empty(sp, O_SHELL, 0))
		return (1);

	/*
	 * XXX
	 * Assumes all shells use -i.
	 */
	(void)asprintf(&buf, "%s -i", O_STR(sp, O_SHELL));
	if (buf == NULL) {
		msgq(sp, M_SYSERR, NULL);
		return (1);
	}

	/* Restore the window name. */
	(void)sp->gp->scr_rename(sp, NULL, 0);

	/* If we're still in a vi screen, move out explicitly. */
	rval = ex_exec_proc(sp, cmdp, buf, NULL, !F_ISSET(sp, SC_SCR_EXWROTE));
	free(buf);

	/* Set the window name. */
	(void)sp->gp->scr_rename(sp, sp->frp->name, 1);

	/*
	 * !!!
	 * Historically, vi didn't require a continue message after the
	 * return of the shell.  Match it.
	 */
	F_SET(sp, SC_EX_WAIT_NO);

	return (rval);
}

/*
 * ex_exec_proc --
 *	Run a separate process.
 *
 * PUBLIC: int ex_exec_proc(SCR *, EXCMD *, char *, const char *, int);
 */
int
ex_exec_proc(SCR *sp, EXCMD *cmdp, char *cmd, const char *msg, int need_newline)
{
	GS *gp;
	const char *name;
	pid_t pid;

	gp = sp->gp;

	/* We'll need a shell. */
	if (opts_empty(sp, O_SHELL, 0))
		return (1);

	/* Enter ex mode. */
	if (F_ISSET(sp, SC_VI)) {
		if (gp->scr_screen(sp, SC_EX)) {
			ex_wemsg(sp, cmdp->cmd->name, EXM_NOCANON);
			return (1);
		}
		(void)gp->scr_attr(sp, SA_ALTERNATE, 0);
		F_SET(sp, SC_SCR_EX | SC_SCR_EXWROTE);
	}

	/* Put out additional newline, message. */
	if (need_newline)
		(void)ex_puts(sp, "\n");
	if (msg != NULL) {
		(void)ex_puts(sp, msg);
		(void)ex_puts(sp, "\n");
	}
	(void)ex_fflush(sp);

	switch (pid = vfork()) {
	case -1:			/* Error. */
		msgq(sp, M_SYSERR, "vfork");
		return (1);
	case 0:				/* Utility. */
		if (gp->scr_child)
			gp->scr_child(sp);
		if ((name = strrchr(O_STR(sp, O_SHELL), '/')) == NULL)
			name = O_STR(sp, O_SHELL);
		else
			++name;
		execl(O_STR(sp, O_SHELL), name, "-c", cmd, (char *)NULL);
		msgq_str(sp, M_SYSERR, O_STR(sp, O_SHELL), "execl: %s");
		_exit(127);
		/* NOTREACHED */
	default:			/* Parent. */
		return (proc_wait(sp, (long)pid, cmd, 0, 0));
	}
	/* NOTREACHED */
}

/*
 * proc_wait --
 *	Wait for one of the processes.
 *
 * !!!
 * The pid_t type varies in size from a short to a long depending on the
 * system.  It has to be cast into something or the standard promotion
 * rules get you.  I'm using a long based on the belief that nobody is
 * going to make it unsigned and it's unlikely to be a quad.
 *
 * PUBLIC: int proc_wait(SCR *, long, const char *, int, int);
 */
int
proc_wait(SCR *sp, long int pid, const char *cmd, int silent, int okpipe)
{
	size_t len;
	int nf, pstat;
	char *p;

	/* Wait for the utility, ignoring interruptions. */
	for (;;) {
		errno = 0;
		if (waitpid((pid_t)pid, &pstat, 0) != -1)
			break;
		if (errno != EINTR) {
			msgq(sp, M_SYSERR, "waitpid");
			return (1);
		}
	}

	/*
	 * Display the utility's exit status.  Ignore SIGPIPE from the
	 * parent-writer, as that only means that the utility chose to
	 * exit before reading all of its input.
	 */
	if (WIFSIGNALED(pstat) && (!okpipe || WTERMSIG(pstat) != SIGPIPE)) {
		for (; cmdskip(*cmd); ++cmd);
		p = msg_print(sp, cmd, &nf);
		len = strlen(p);
		msgq(sp, M_ERR, "%.*s%s: received signal: %s%s",
		    (int)MIN(len, 20), p, len > 20 ? " ..." : "",
		    sigmsg(WTERMSIG(pstat)),
		    WCOREDUMP(pstat) ? "; core dumped" : "");
		if (nf)
			FREE_SPACE(sp, p, 0);
		return (1);
	}

	if (WIFEXITED(pstat) && WEXITSTATUS(pstat)) {
		/*
		 * Remain silent for "normal" errors when doing shell file
		 * name expansions, they almost certainly indicate nothing
		 * more than a failure to match.
		 *
		 * Remain silent for vi read filter errors.  It's historic
		 * practice.
		 */
		if (!silent) {
			for (; cmdskip(*cmd); ++cmd);
			p = msg_print(sp, cmd, &nf);
			len = strlen(p);
			msgq(sp, M_ERR, "%.*s%s: exited with status %d",
			    (int)MIN(len, 20), p, len > 20 ? " ..." : "",
			    WEXITSTATUS(pstat));
			if (nf)
				FREE_SPACE(sp, p, 0);
		}
		return (1);
	}
	return (0);
}

/*
 * sigmsg --
 * 	Return a pointer to a message describing a signal.
 */
static const char *
sigmsg(int signo)
{
	static char buf[40];
	char *message;

	/* POSIX.1-2008 leaves strsignal(3)'s return value unspecified. */
	if ((message = strsignal(signo)) != NULL)
		return message;
	(void)snprintf(buf, sizeof(buf), "Unknown signal: %d", signo);
	return (buf);
}