output.c

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Shell output routines.  We use our own output routines because:
 *	When a builtin command is interrupted we have to discard
 *		any pending output.
 *	When a builtin command appears in back quotes, we want to
 *		save the output of the command in a region obtained
 *		via malloc, rather than doing a fork and reading the
 *		output of the command via a pipe.
 */

#include <stdio.h>	/* defines BUFSIZ */
#include <string.h>
#include <stdarg.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <wchar.h>
#include <wctype.h>

#include "shell.h"
#include "syntax.h"
#include "output.h"
#include "memalloc.h"
#include "error.h"
#include "var.h"


#define OUTBUFSIZ BUFSIZ
#define MEM_OUT -2		/* output to dynamically allocated memory */
#define OUTPUT_ERR 01		/* error occurred on output */

static int doformat_wr(void *, const char *, int);

struct output output = {NULL, NULL, NULL, OUTBUFSIZ, 1, 0};
struct output errout = {NULL, NULL, NULL, 256, 2, 0};
struct output memout = {NULL, NULL, NULL, 64, MEM_OUT, 0};
struct output *out1 = &output;
struct output *out2 = &errout;

void
outcslow(int c, struct output *file)
{
	outc(c, file);
}

void
out1str(const char *p)
{
	outstr(p, out1);
}

void
out1qstr(const char *p)
{
	outqstr(p, out1);
}

void
out2str(const char *p)
{
	outstr(p, out2);
}

void
out2qstr(const char *p)
{
	outqstr(p, out2);
}

void
outstr(const char *p, struct output *file)
{
	outbin(p, strlen(p), file);
}

static void
byteseq(int ch, struct output *file)
{
	char seq[4];

	seq[0] = '\\';
	seq[1] = (ch >> 6 & 0x3) + '0';
	seq[2] = (ch >> 3 & 0x7) + '0';
	seq[3] = (ch & 0x7) + '0';
	outbin(seq, 4, file);
}

static void
outdqstr(const char *p, struct output *file)
{
	const char *end;
	mbstate_t mbs;
	size_t clen;
	wchar_t wc;

	memset(&mbs, '\0', sizeof(mbs));
	end = p + strlen(p);
	outstr("$'", file);
	while ((clen = mbrtowc(&wc, p, end - p + 1, &mbs)) != 0) {
		if (clen == (size_t)-2) {
			while (p < end)
				byteseq(*p++, file);
			break;
		}
		if (clen == (size_t)-1) {
			memset(&mbs, '\0', sizeof(mbs));
			byteseq(*p++, file);
			continue;
		}
		if (wc == L'\n')
			outcslow('\n', file), p++;
		else if (wc == L'\r')
			outstr("\\r", file), p++;
		else if (wc == L'\t')
			outstr("\\t", file), p++;
		else if (!iswprint(wc)) {
			for (; clen > 0; clen--)
				byteseq(*p++, file);
		} else {
			if (wc == L'\'' || wc == L'\\')
				outcslow('\\', file);
			outbin(p, clen, file);
			p += clen;
		}
	}
	outcslow('\'', file);
}

/* Like outstr(), but quote for re-input into the shell. */
void
outqstr(const char *p, struct output *file)
{
	int i;

	if (p[0] == '\0') {
		outstr("''", file);
		return;
	}
	for (i = 0; p[i] != '\0'; i++) {
		if ((p[i] > '\0' && p[i] < ' ' && p[i] != '\n') ||
		    (p[i] & 0x80) != 0 || p[i] == '\'') {
			outdqstr(p, file);
			return;
		}
	}

	if (p[strcspn(p, "|&;<>()$`\\\" \n*?[~#=")] == '\0' ||
			strcmp(p, "[") == 0) {
		outstr(p, file);
		return;
	}

	outcslow('\'', file);
	outstr(p, file);
	outcslow('\'', file);
}

void
outbin(const void *data, size_t len, struct output *file)
{
	const char *p;

	p = data;
	while (len-- > 0)
		outc(*p++, file);
}

void
emptyoutbuf(struct output *dest)
{
	int offset, newsize;

	if (dest->buf == NULL) {
		INTOFF;
		dest->buf = ckmalloc(dest->bufsize);
		dest->nextc = dest->buf;
		dest->bufend = dest->buf + dest->bufsize;
		INTON;
	} else if (dest->fd == MEM_OUT) {
		offset = dest->nextc - dest->buf;
		newsize = dest->bufsize << 1;
		INTOFF;
		dest->buf = ckrealloc(dest->buf, newsize);
		dest->bufsize = newsize;
		dest->bufend = dest->buf + newsize;
		dest->nextc = dest->buf + offset;
		INTON;
	} else {
		flushout(dest);
	}
}


void
flushall(void)
{
	flushout(&output);
	flushout(&errout);
}


void
flushout(struct output *dest)
{

	if (dest->buf == NULL || dest->nextc == dest->buf || dest->fd < 0)
		return;
	if (xwrite(dest->fd, dest->buf, dest->nextc - dest->buf) < 0)
		dest->flags |= OUTPUT_ERR;
	dest->nextc = dest->buf;
}


void
freestdout(void)
{
	output.nextc = output.buf;
}


int
outiserror(struct output *file)
{
	return (file->flags & OUTPUT_ERR);
}


void
outclearerror(struct output *file)
{
	file->flags &= ~OUTPUT_ERR;
}


void
outfmt(struct output *file, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	doformat(file, fmt, ap);
	va_end(ap);
}


void
out1fmt(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	doformat(out1, fmt, ap);
	va_end(ap);
}

void
out2fmt_flush(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	doformat(out2, fmt, ap);
	va_end(ap);
	flushout(out2);
}

void
fmtstr(char *outbuf, int length, const char *fmt, ...)
{
	va_list ap;

	INTOFF;
	va_start(ap, fmt);
	vsnprintf(outbuf, length, fmt, ap);
	va_end(ap);
	INTON;
}

static int
doformat_wr(void *cookie, const char *buf, int len)
{
	struct output *o;

	o = (struct output *)cookie;
	outbin(buf, len, o);

	return (len);
}

void
doformat(struct output *dest, const char *f, va_list ap)
{
	FILE *fp;

	if ((fp = fwopen(dest, doformat_wr)) != NULL) {
		vfprintf(fp, f, ap);
		fclose(fp);
	}
}

FILE *
out1fp(void)
{
	return fwopen(out1, doformat_wr);
}

/*
 * Version of write which resumes after a signal is caught.
 */

int
xwrite(int fd, const char *buf, int nbytes)
{
	int ntry;
	int i;
	int n;

	n = nbytes;
	ntry = 0;
	for (;;) {
		i = write(fd, buf, n);
		if (i > 0) {
			if ((n -= i) <= 0)
				return nbytes;
			buf += i;
			ntry = 0;
		} else if (i == 0) {
			if (++ntry > 10)
				return nbytes - n;
		} else if (errno != EINTR) {
			return -1;
		}
	}
}