minix3/commands/grep/file.c

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2020-02-21 00:59:27 +05:30
/* $OpenBSD: file.c,v 1.9 2006/02/09 09:54:46 otto Exp $ */
/*-
* Copyright (c) 1999 James Howard and Dag-Erling Co<EFBFBD>dan Sm<EFBFBD>rgrav
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/param.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "grep.h"
static char fname[MAXPATHLEN];
#ifndef NOZ
static char *lnbuf;
static size_t lnbuflen;
#endif
#define FILE_STDIO 0
#define FILE_MMAP 1
#define FILE_GZIP 2
struct file {
int type;
int noseek;
FILE *f;
mmf_t *mmf;
#ifndef NOZ
gzFile *gzf;
#endif
};
#ifndef NOZ
static char *
gzfgetln(gzFile *f, size_t *len)
{
size_t n;
int c;
for (n = 0; ; ++n) {
c = gzgetc(f);
if (c == -1) {
const char *gzerrstr;
int gzerr;
if (gzeof(f))
break;
gzerrstr = gzerror(f, &gzerr);
if (gzerr == Z_ERRNO)
err(2, "%s", fname);
else
errx(2, "%s: %s", fname, gzerrstr);
}
if (n >= lnbuflen) {
lnbuflen *= 2;
lnbuf = grep_realloc(lnbuf, ++lnbuflen);
}
if (c == '\n')
break;
lnbuf[n] = c;
}
if (gzeof(f) && n == 0)
return NULL;
*len = n;
return lnbuf;
}
#endif
file_t *
grep_fdopen(int fd, char *mode)
{
file_t *f;
if (fd == STDIN_FILENO)
snprintf(fname, sizeof fname, "(standard input)");
else
snprintf(fname, sizeof fname, "(fd %d)", fd);
f = grep_malloc(sizeof *f);
#ifndef NOZ
if (Zflag) {
f->type = FILE_GZIP;
f->noseek = lseek(fd, 0L, SEEK_SET) == -1;
if ((f->gzf = gzdopen(fd, mode)) != NULL)
return f;
} else
#endif
{
f->type = FILE_STDIO;
f->noseek = isatty(fd);
if ((f->f = fdopen(fd, mode)) != NULL)
return f;
}
free(f);
return NULL;
}
file_t *
grep_open(char *path, char *mode)
{
file_t *f;
snprintf(fname, sizeof fname, "%s", path);
f = grep_malloc(sizeof *f);
f->noseek = 0;
#ifndef NOZ
if (Zflag) {
f->type = FILE_GZIP;
if ((f->gzf = gzopen(fname, mode)) != NULL)
return f;
} else
#endif
{
#ifdef FILE_MMAP
/* try mmap first; if it fails, try stdio */
if ((f->mmf = mmopen(fname, mode)) != NULL) {
f->type = FILE_MMAP;
return f;
}
#endif
f->type = FILE_STDIO;
if ((f->f = fopen(path, mode)) != NULL)
return f;
}
free(f);
return NULL;
}
int
grep_bin_file(file_t *f)
{
if (f->noseek)
return 0;
switch (f->type) {
case FILE_STDIO:
return bin_file(f->f);
#ifdef FILE_MMAP
case FILE_MMAP:
return mmbin_file(f->mmf);
#endif
#ifndef NOZ
case FILE_GZIP:
return gzbin_file(f->gzf);
#endif
default:
/* can't happen */
errx(2, "invalid file type");
}
}
char *
grep_fgetln(file_t *f, size_t *l)
{
switch (f->type) {
case FILE_STDIO:
return fgetln(f->f, l);
#ifdef FILE_MMAP
case FILE_MMAP:
return mmfgetln(f->mmf, l);
#endif
#ifndef NOZ
case FILE_GZIP:
return gzfgetln(f->gzf, l);
#endif
default:
/* can't happen */
errx(2, "invalid file type");
}
}
void
grep_close(file_t *f)
{
switch (f->type) {
case FILE_STDIO:
fclose(f->f);
break;
#ifdef FILE_MMAP
case FILE_MMAP:
mmclose(f->mmf);
break;
#endif
#ifndef NOZ
case FILE_GZIP:
gzclose(f->gzf);
break;
#endif
default:
/* can't happen */
errx(2, "invalid file type");
}
free(f);
}