xref: /dragonfly/contrib/nvi2/ex/ex_shell.c (revision 2b7dbe20)
1 /*-
2  * Copyright (c) 1992, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #include <sys/queue.h>
13 #include <sys/time.h>
14 #include <sys/wait.h>
15 
16 #include <bitstring.h>
17 #include <ctype.h>
18 #include <errno.h>
19 #include <limits.h>
20 #include <signal.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25 
26 #include "../common/common.h"
27 
28 static const char *sigmsg(int);
29 
30 /*
31  * ex_shell -- :sh[ell]
32  *	Invoke the program named in the SHELL environment variable
33  *	with the argument -i.
34  *
35  * PUBLIC: int ex_shell(SCR *, EXCMD *);
36  */
37 int
38 ex_shell(SCR *sp, EXCMD *cmdp)
39 {
40 	int rval;
41 	char *buf;
42 
43 	/* We'll need a shell. */
44 	if (opts_empty(sp, O_SHELL, 0))
45 		return (1);
46 
47 	/*
48 	 * XXX
49 	 * Assumes all shells use -i.
50 	 */
51 	if (asprintf(&buf, "%s -i", O_STR(sp, O_SHELL)) == -1) {
52 		msgq(sp, M_SYSERR, NULL);
53 		return (1);
54 	}
55 
56 	/* Restore the window name. */
57 	(void)sp->gp->scr_rename(sp, NULL, 0);
58 
59 	/* If we're still in a vi screen, move out explicitly. */
60 	rval = ex_exec_proc(sp, cmdp, buf, NULL, !F_ISSET(sp, SC_SCR_EXWROTE));
61 	free(buf);
62 
63 	/* Set the window name. */
64 	(void)sp->gp->scr_rename(sp, sp->frp->name, 1);
65 
66 	/*
67 	 * !!!
68 	 * Historically, vi didn't require a continue message after the
69 	 * return of the shell.  Match it.
70 	 */
71 	F_SET(sp, SC_EX_WAIT_NO);
72 
73 	return (rval);
74 }
75 
76 /*
77  * ex_exec_proc --
78  *	Run a separate process.
79  *
80  * PUBLIC: int ex_exec_proc(SCR *, EXCMD *, char *, const char *, int);
81  */
82 int
83 ex_exec_proc(SCR *sp, EXCMD *cmdp, char *cmd, const char *msg, int need_newline)
84 {
85 	GS *gp;
86 	const char *name;
87 	pid_t pid;
88 
89 	gp = sp->gp;
90 
91 	/* We'll need a shell. */
92 	if (opts_empty(sp, O_SHELL, 0))
93 		return (1);
94 
95 	/* Enter ex mode. */
96 	if (F_ISSET(sp, SC_VI)) {
97 		if (gp->scr_screen(sp, SC_EX)) {
98 			ex_wemsg(sp, cmdp->cmd->name, EXM_NOCANON);
99 			return (1);
100 		}
101 		(void)gp->scr_attr(sp, SA_ALTERNATE, 0);
102 		F_SET(sp, SC_SCR_EX | SC_SCR_EXWROTE);
103 	}
104 
105 	/* Put out additional newline, message. */
106 	if (need_newline)
107 		(void)ex_puts(sp, "\n");
108 	if (msg != NULL) {
109 		(void)ex_puts(sp, msg);
110 		(void)ex_puts(sp, "\n");
111 	}
112 	(void)ex_fflush(sp);
113 
114 	switch (pid = vfork()) {
115 	case -1:			/* Error. */
116 		msgq(sp, M_SYSERR, "vfork");
117 		return (1);
118 	case 0:				/* Utility. */
119 		if (gp->scr_child)
120 			gp->scr_child(sp);
121 		if ((name = strrchr(O_STR(sp, O_SHELL), '/')) == NULL)
122 			name = O_STR(sp, O_SHELL);
123 		else
124 			++name;
125 		execl(O_STR(sp, O_SHELL), name, "-c", cmd, (char *)NULL);
126 		msgq_str(sp, M_SYSERR, O_STR(sp, O_SHELL), "execl: %s");
127 		_exit(127);
128 		/* NOTREACHED */
129 	default:			/* Parent. */
130 		return (proc_wait(sp, (long)pid, cmd, 0, 0));
131 	}
132 	/* NOTREACHED */
133 }
134 
135 /*
136  * proc_wait --
137  *	Wait for one of the processes.
138  *
139  * !!!
140  * The pid_t type varies in size from a short to a long depending on the
141  * system.  It has to be cast into something or the standard promotion
142  * rules get you.  I'm using a long based on the belief that nobody is
143  * going to make it unsigned and it's unlikely to be a quad.
144  *
145  * PUBLIC: int proc_wait(SCR *, long, const char *, int, int);
146  */
147 int
148 proc_wait(SCR *sp, long int pid, const char *cmd, int silent, int okpipe)
149 {
150 	size_t len;
151 	int nf, pstat;
152 	char *p;
153 
154 	/* Wait for the utility, ignoring interruptions. */
155 	for (;;) {
156 		errno = 0;
157 		if (waitpid((pid_t)pid, &pstat, 0) != -1)
158 			break;
159 		if (errno != EINTR) {
160 			msgq(sp, M_SYSERR, "waitpid");
161 			return (1);
162 		}
163 	}
164 
165 	/*
166 	 * Display the utility's exit status.  Ignore SIGPIPE from the
167 	 * parent-writer, as that only means that the utility chose to
168 	 * exit before reading all of its input.
169 	 */
170 	if (WIFSIGNALED(pstat) && (!okpipe || WTERMSIG(pstat) != SIGPIPE)) {
171 		for (; cmdskip(*cmd); ++cmd);
172 		p = msg_print(sp, cmd, &nf);
173 		len = strlen(p);
174 		msgq(sp, M_ERR, "%.*s%s: received signal: %s%s",
175 		    (int)MIN(len, 20), p, len > 20 ? " ..." : "",
176 		    sigmsg(WTERMSIG(pstat)),
177 		    WCOREDUMP(pstat) ? "; core dumped" : "");
178 		if (nf)
179 			FREE_SPACE(sp, p, 0);
180 		return (1);
181 	}
182 
183 	if (WIFEXITED(pstat) && WEXITSTATUS(pstat)) {
184 		/*
185 		 * Remain silent for "normal" errors when doing shell file
186 		 * name expansions, they almost certainly indicate nothing
187 		 * more than a failure to match.
188 		 *
189 		 * Remain silent for vi read filter errors.  It's historic
190 		 * practice.
191 		 */
192 		if (!silent) {
193 			for (; cmdskip(*cmd); ++cmd);
194 			p = msg_print(sp, cmd, &nf);
195 			len = strlen(p);
196 			msgq(sp, M_ERR, "%.*s%s: exited with status %d",
197 			    (int)MIN(len, 20), p, len > 20 ? " ..." : "",
198 			    WEXITSTATUS(pstat));
199 			if (nf)
200 				FREE_SPACE(sp, p, 0);
201 		}
202 		return (1);
203 	}
204 	return (0);
205 }
206 
207 /*
208  * sigmsg --
209  * 	Return a pointer to a message describing a signal.
210  */
211 static const char *
212 sigmsg(int signo)
213 {
214 	static char buf[40];
215 	char *message;
216 
217 	/* POSIX.1-2008 leaves strsignal(3)'s return value unspecified. */
218 	if ((message = strsignal(signo)) != NULL)
219 		return message;
220 	(void)snprintf(buf, sizeof(buf), "Unknown signal: %d", signo);
221 	return (buf);
222 }
223