xref: /onnv-gate/usr/src/lib/libproc/common/proc_stdio.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate /*
30*0Sstevel@tonic-gate  * Utility functions for buffering output to stdout, stderr while
31*0Sstevel@tonic-gate  * process is grabbed.  Prevents infamous deadlocks due to pfiles `pgrep xterm`
32*0Sstevel@tonic-gate  * and other varients.
33*0Sstevel@tonic-gate  */
34*0Sstevel@tonic-gate 
35*0Sstevel@tonic-gate #include "libproc.h"
36*0Sstevel@tonic-gate #include <stdio.h>
37*0Sstevel@tonic-gate 
38*0Sstevel@tonic-gate static int cached_stdout_fd = -1;
39*0Sstevel@tonic-gate static int cached_stderr_fd = -1;
40*0Sstevel@tonic-gate static int initialized = 0;
41*0Sstevel@tonic-gate 
42*0Sstevel@tonic-gate static char stdout_name[] = "/tmp/.stdoutXXXXXX";
43*0Sstevel@tonic-gate static char stderr_name[] = "/tmp/.stderrXXXXXX";
44*0Sstevel@tonic-gate 
45*0Sstevel@tonic-gate int
proc_initstdio(void)46*0Sstevel@tonic-gate proc_initstdio(void)
47*0Sstevel@tonic-gate {
48*0Sstevel@tonic-gate 	int fd;
49*0Sstevel@tonic-gate 
50*0Sstevel@tonic-gate 	(void) fflush(stdout);
51*0Sstevel@tonic-gate 	(void) fflush(stderr);
52*0Sstevel@tonic-gate 
53*0Sstevel@tonic-gate 	if ((cached_stdout_fd = dup(1)) < 0) {
54*0Sstevel@tonic-gate 		return (-1);
55*0Sstevel@tonic-gate 	}
56*0Sstevel@tonic-gate 
57*0Sstevel@tonic-gate 	if ((cached_stderr_fd = dup(2)) < 0) {
58*0Sstevel@tonic-gate 		(void) close(cached_stdout_fd);
59*0Sstevel@tonic-gate 		return (-1);
60*0Sstevel@tonic-gate 	}
61*0Sstevel@tonic-gate 
62*0Sstevel@tonic-gate 	if ((fd = mkstemp(stdout_name)) < 0) {
63*0Sstevel@tonic-gate 		(void) close(cached_stdout_fd);
64*0Sstevel@tonic-gate 		(void) close(cached_stderr_fd);
65*0Sstevel@tonic-gate 		return (-1);
66*0Sstevel@tonic-gate 	}
67*0Sstevel@tonic-gate 
68*0Sstevel@tonic-gate 	(void) unlink(stdout_name);
69*0Sstevel@tonic-gate 
70*0Sstevel@tonic-gate 	if (dup2(fd, 1) < 0) {
71*0Sstevel@tonic-gate 		(void) close(fd);
72*0Sstevel@tonic-gate 		(void) close(cached_stdout_fd);
73*0Sstevel@tonic-gate 		(void) close(cached_stderr_fd);
74*0Sstevel@tonic-gate 		return (-1);
75*0Sstevel@tonic-gate 	}
76*0Sstevel@tonic-gate 
77*0Sstevel@tonic-gate 	(void) close(fd);
78*0Sstevel@tonic-gate 
79*0Sstevel@tonic-gate 
80*0Sstevel@tonic-gate 	if ((fd = mkstemp(stderr_name)) < 0) {
81*0Sstevel@tonic-gate 		(void) dup2(cached_stdout_fd, 1);
82*0Sstevel@tonic-gate 		(void) close(cached_stdout_fd);
83*0Sstevel@tonic-gate 		(void) close(cached_stderr_fd);
84*0Sstevel@tonic-gate 		return (-1);
85*0Sstevel@tonic-gate 	}
86*0Sstevel@tonic-gate 
87*0Sstevel@tonic-gate 	(void) unlink(stderr_name);
88*0Sstevel@tonic-gate 
89*0Sstevel@tonic-gate 	if (dup2(fd, 2) < 0) {
90*0Sstevel@tonic-gate 		(void) close(fd);
91*0Sstevel@tonic-gate 		(void) dup2(cached_stdout_fd, 1);
92*0Sstevel@tonic-gate 		(void) close(cached_stdout_fd);
93*0Sstevel@tonic-gate 		(void) dup2(cached_stderr_fd, 2);
94*0Sstevel@tonic-gate 		(void) close(cached_stderr_fd);
95*0Sstevel@tonic-gate 		(void) close(fd);
96*0Sstevel@tonic-gate 		return (-1);
97*0Sstevel@tonic-gate 	}
98*0Sstevel@tonic-gate 
99*0Sstevel@tonic-gate 	(void) close(fd);
100*0Sstevel@tonic-gate 
101*0Sstevel@tonic-gate 	initialized = 1;
102*0Sstevel@tonic-gate 
103*0Sstevel@tonic-gate 	return (0);
104*0Sstevel@tonic-gate }
105*0Sstevel@tonic-gate 
106*0Sstevel@tonic-gate static int
copy_fd(int out,FILE * in,size_t len)107*0Sstevel@tonic-gate copy_fd(int out, FILE *in, size_t len)
108*0Sstevel@tonic-gate {
109*0Sstevel@tonic-gate 	char buffer[8192];
110*0Sstevel@tonic-gate 	int rlen, alen;
111*0Sstevel@tonic-gate 	int errors = 0;
112*0Sstevel@tonic-gate 
113*0Sstevel@tonic-gate 	rewind(in);
114*0Sstevel@tonic-gate 	while (len > 0 && !errors) {
115*0Sstevel@tonic-gate 		rlen = (len > sizeof (buffer)) ? sizeof (buffer) : len;
116*0Sstevel@tonic-gate 		alen = read(fileno(in), buffer, rlen);
117*0Sstevel@tonic-gate 		if (alen == rlen) {
118*0Sstevel@tonic-gate 			if (write(out, buffer, alen) < alen)
119*0Sstevel@tonic-gate 				errors++;
120*0Sstevel@tonic-gate 			else
121*0Sstevel@tonic-gate 				len -= alen;
122*0Sstevel@tonic-gate 		}
123*0Sstevel@tonic-gate 		else
124*0Sstevel@tonic-gate 			errors++;
125*0Sstevel@tonic-gate 	}
126*0Sstevel@tonic-gate 	rewind(in);
127*0Sstevel@tonic-gate 	return (errors);
128*0Sstevel@tonic-gate }
129*0Sstevel@tonic-gate 
130*0Sstevel@tonic-gate int
proc_flushstdio(void)131*0Sstevel@tonic-gate proc_flushstdio(void)
132*0Sstevel@tonic-gate {
133*0Sstevel@tonic-gate 	size_t len;
134*0Sstevel@tonic-gate 	int errors = 0;
135*0Sstevel@tonic-gate 
136*0Sstevel@tonic-gate 	/*
137*0Sstevel@tonic-gate 	 * flush any pending IO
138*0Sstevel@tonic-gate 	 */
139*0Sstevel@tonic-gate 
140*0Sstevel@tonic-gate 	if (!initialized)
141*0Sstevel@tonic-gate 		return (-1);
142*0Sstevel@tonic-gate 
143*0Sstevel@tonic-gate 	(void) fflush(stdout);
144*0Sstevel@tonic-gate 	(void) fflush(stderr);
145*0Sstevel@tonic-gate 
146*0Sstevel@tonic-gate 	if ((len = ftell(stdout)) > 0)
147*0Sstevel@tonic-gate 		errors += copy_fd(cached_stdout_fd, stdout, len);
148*0Sstevel@tonic-gate 
149*0Sstevel@tonic-gate 
150*0Sstevel@tonic-gate 	if ((len = ftell(stderr)) > 0)
151*0Sstevel@tonic-gate 		errors += copy_fd(cached_stderr_fd, stderr, len);
152*0Sstevel@tonic-gate 
153*0Sstevel@tonic-gate 	return (errors?-1:0);
154*0Sstevel@tonic-gate }
155*0Sstevel@tonic-gate 
156*0Sstevel@tonic-gate int
proc_finistdio(void)157*0Sstevel@tonic-gate proc_finistdio(void)
158*0Sstevel@tonic-gate {
159*0Sstevel@tonic-gate 	if (!initialized)
160*0Sstevel@tonic-gate 		return (-1);
161*0Sstevel@tonic-gate 
162*0Sstevel@tonic-gate 	if (proc_flushstdio() != 0)
163*0Sstevel@tonic-gate 		return (-1);
164*0Sstevel@tonic-gate 
165*0Sstevel@tonic-gate 	(void) dup2(cached_stdout_fd, 1);
166*0Sstevel@tonic-gate 	(void) close(cached_stdout_fd);
167*0Sstevel@tonic-gate 	(void) dup2(cached_stderr_fd, 2);
168*0Sstevel@tonic-gate 	(void) close(cached_stderr_fd);
169*0Sstevel@tonic-gate 
170*0Sstevel@tonic-gate 	return (0);
171*0Sstevel@tonic-gate }
172