output.c revision 215567 
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)output.c	8.2 (Berkeley) 5/4/95";
36#endif
37#endif /* not lint */
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/bin/sh/output.c 215567 2010-11-20 14:14:52Z jilles $");
40
41/*
42 * Shell output routines.  We use our own output routines because:
43 *	When a builtin command is interrupted we have to discard
44 *		any pending output.
45 *	When a builtin command appears in back quotes, we want to
46 *		save the output of the command in a region obtained
47 *		via malloc, rather than doing a fork and reading the
48 *		output of the command via a pipe.
49 */
50
51#include <stdio.h>	/* defines BUFSIZ */
52#include <string.h>
53#include <stdarg.h>
54#include <errno.h>
55#include <unistd.h>
56#include <stdlib.h>
57
58#include "shell.h"
59#include "syntax.h"
60#include "output.h"
61#include "memalloc.h"
62#include "error.h"
63#include "var.h"
64
65
66#define OUTBUFSIZ BUFSIZ
67#define BLOCK_OUT -2		/* output to a fixed block of memory */
68#define MEM_OUT -3		/* output to dynamically allocated memory */
69#define OUTPUT_ERR 01		/* error occurred on output */
70
71static int doformat_wr(void *, const char *, int);
72
73struct output output = {NULL, 0, NULL, OUTBUFSIZ, 1, 0};
74struct output errout = {NULL, 0, NULL, 256, 2, 0};
75struct output memout = {NULL, 0, NULL, 0, MEM_OUT, 0};
76struct output *out1 = &output;
77struct output *out2 = &errout;
78
79
80
81#ifdef mkinit
82
83INCLUDE "output.h"
84INCLUDE "memalloc.h"
85
86RESET {
87	out1 = &output;
88	out2 = &errout;
89	if (memout.buf != NULL) {
90		ckfree(memout.buf);
91		memout.buf = NULL;
92	}
93}
94
95#endif
96
97
98void
99outcslow(int c, struct output *file)
100{
101	outc(c, file);
102}
103
104void
105out1str(const char *p)
106{
107	outstr(p, out1);
108}
109
110void
111out1qstr(const char *p)
112{
113	outqstr(p, out1);
114}
115
116void
117out2str(const char *p)
118{
119	outstr(p, out2);
120}
121
122void
123out2qstr(const char *p)
124{
125	outqstr(p, out2);
126}
127
128void
129outstr(const char *p, struct output *file)
130{
131	outbin(p, strlen(p), file);
132}
133
134/* Like outstr(), but quote for re-input into the shell. */
135void
136outqstr(const char *p, struct output *file)
137{
138	char ch;
139	int inquotes;
140
141	if (p[0] == '\0') {
142		outstr("''", file);
143		return;
144	}
145	/* Caller will handle '=' if necessary */
146	if (p[strcspn(p, "|&;<>()$`\\\"' \t\n*?[~#")] == '\0' ||
147			strcmp(p, "[") == 0) {
148		outstr(p, file);
149		return;
150	}
151
152	inquotes = 0;
153	while ((ch = *p++) != '\0') {
154		switch (ch) {
155		case '\'':
156			/* Can't quote single quotes inside single quotes. */
157			if (inquotes)
158				outcslow('\'', file);
159			inquotes = 0;
160			outstr("\\'", file);
161			break;
162		default:
163			if (!inquotes)
164				outcslow('\'', file);
165			inquotes = 1;
166			outc(ch, file);
167		}
168	}
169	if (inquotes)
170		outcslow('\'', file);
171}
172
173void
174outbin(const void *data, size_t len, struct output *file)
175{
176	const char *p;
177
178	p = data;
179	while (len-- > 0)
180		outc(*p++, file);
181}
182
183static char out_junk[16];
184
185void
186emptyoutbuf(struct output *dest)
187{
188	int offset;
189
190	if (dest->fd == BLOCK_OUT) {
191		dest->nextc = out_junk;
192		dest->nleft = sizeof out_junk;
193		dest->flags |= OUTPUT_ERR;
194	} else if (dest->buf == NULL) {
195		INTOFF;
196		dest->buf = ckmalloc(dest->bufsize);
197		dest->nextc = dest->buf;
198		dest->nleft = dest->bufsize;
199		INTON;
200	} else if (dest->fd == MEM_OUT) {
201		offset = dest->bufsize;
202		INTOFF;
203		dest->bufsize <<= 1;
204		dest->buf = ckrealloc(dest->buf, dest->bufsize);
205		dest->nleft = dest->bufsize - offset;
206		dest->nextc = dest->buf + offset;
207		INTON;
208	} else {
209		flushout(dest);
210	}
211	dest->nleft--;
212}
213
214
215void
216flushall(void)
217{
218	flushout(&output);
219	flushout(&errout);
220}
221
222
223void
224flushout(struct output *dest)
225{
226
227	if (dest->buf == NULL || dest->nextc == dest->buf || dest->fd < 0)
228		return;
229	if (xwrite(dest->fd, dest->buf, dest->nextc - dest->buf) < 0)
230		dest->flags |= OUTPUT_ERR;
231	dest->nextc = dest->buf;
232	dest->nleft = dest->bufsize;
233}
234
235
236void
237freestdout(void)
238{
239	INTOFF;
240	if (output.buf) {
241		ckfree(output.buf);
242		output.buf = NULL;
243		output.nleft = 0;
244	}
245	INTON;
246}
247
248
249void
250outfmt(struct output *file, const char *fmt, ...)
251{
252	va_list ap;
253
254	va_start(ap, fmt);
255	doformat(file, fmt, ap);
256	va_end(ap);
257}
258
259
260void
261out1fmt(const char *fmt, ...)
262{
263	va_list ap;
264
265	va_start(ap, fmt);
266	doformat(out1, fmt, ap);
267	va_end(ap);
268}
269
270void
271out2fmt_flush(const char *fmt, ...)
272{
273	va_list ap;
274
275	va_start(ap, fmt);
276	doformat(out2, fmt, ap);
277	va_end(ap);
278	flushout(out2);
279}
280
281void
282fmtstr(char *outbuf, int length, const char *fmt, ...)
283{
284	va_list ap;
285	struct output strout;
286
287	strout.nextc = outbuf;
288	strout.nleft = length;
289	strout.fd = BLOCK_OUT;
290	strout.flags = 0;
291	va_start(ap, fmt);
292	doformat(&strout, fmt, ap);
293	va_end(ap);
294	outc('\0', &strout);
295	if (strout.flags & OUTPUT_ERR)
296		outbuf[length - 1] = '\0';
297}
298
299static int
300doformat_wr(void *cookie, const char *buf, int len)
301{
302	struct output *o;
303
304	o = (struct output *)cookie;
305	outbin(buf, len, o);
306
307	return (len);
308}
309
310void
311doformat(struct output *dest, const char *f, va_list ap)
312{
313	FILE *fp;
314
315	if ((fp = fwopen(dest, doformat_wr)) != NULL) {
316		vfprintf(fp, f, ap);
317		fclose(fp);
318	}
319}
320
321/*
322 * Version of write which resumes after a signal is caught.
323 */
324
325int
326xwrite(int fd, const char *buf, int nbytes)
327{
328	int ntry;
329	int i;
330	int n;
331
332	n = nbytes;
333	ntry = 0;
334	for (;;) {
335		i = write(fd, buf, n);
336		if (i > 0) {
337			if ((n -= i) <= 0)
338				return nbytes;
339			buf += i;
340			ntry = 0;
341		} else if (i == 0) {
342			if (++ntry > 10)
343				return nbytes - n;
344		} else if (errno != EINTR) {
345			return -1;
346		}
347	}
348}
349