root/libswish3/trunk/src/libswish3/io.c

/*
 * This file is part of libswish3
 * Copyright (C) 2007 Peter Karman
 *
 *  libswish3 is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  libswish3 is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with libswish3; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

/* simple I/O functions */

#include <stdio.h>
#include <errno.h>
#include <err.h>
#include <string.h>

#include "libswish3.h"

extern int SWISH_DEBUG;
extern int errno;

static void no_nulls(
    xmlChar *filename,
    xmlChar *buffer,
    int bytes_read
);

/* substitute embedded null chars with a newline so we can treat the buffer as a whole
 * string based on similar code in swish-e ver2 file.c */
static void
no_nulls(
    xmlChar *filename,
    xmlChar *buffer,
    int bytes_read
)
{
    if (xmlStrlen(buffer) < bytes_read) {
        int i;
        int j = 0;
        int i_bytes_read = (int)bytes_read;

        for (i = 0; i < i_bytes_read; ++i) {
            if (buffer[i] == '\0') {
                buffer[i] = '\n';
                j++;
            }
            if (buffer[i] == SWISH_TOKENPOS_BUMPER[0]) {
                buffer[i] = '\n';
                j++;
            }
        }

        if (j) {
            SWISH_WARN
                ("Substituted %d embedded null or connector character(s) in file '%s' with newline(s)",
                 j, filename);
        }
    }

}

xmlChar *
swish_slurp_fh(
    FILE * fh,
    long flen
)
{

    size_t bytes_read;
    xmlChar *buffer;

/* printf("slurping %d bytes\n", flen); */

    buffer = swish_xmalloc(flen + 1);
    *buffer = '\0';

    bytes_read = fread(buffer, sizeof(xmlChar), flen, fh);

    if (bytes_read != flen) {
        SWISH_CROAK("did not read expected bytes: %ld expected, %d read", flen,
                    bytes_read);
    }
    buffer[bytes_read] = '\0';  /* terminate the string */

/* printf("read %d bytes from stdin\n", bytes_read); */

    no_nulls((xmlChar *)"filehandle", buffer, (int)bytes_read);

    return buffer;
}

xmlChar *
swish_slurp_file_len(
    xmlChar *filename,
    long flen
)
{
    size_t bytes_read;
    FILE *fp;
    xmlChar *buffer;

    if (flen > SWISH_MAX_FILE_LEN) {
        flen = SWISH_MAX_FILE_LEN;
        SWISH_WARN("max file len %ld exceeded - cannot read %ld bytes from %s",
                   SWISH_MAX_FILE_LEN, flen, filename);

    }

    buffer = swish_xmalloc(flen + 1);

    if ((fp = fopen((char *)filename, "r")) == 0) {
        SWISH_CROAK("Error reading file %s: %s", filename, strerror(errno));
    }

    bytes_read = fread(buffer, sizeof(xmlChar), flen, fp);

    if (bytes_read != flen) {
        SWISH_CROAK("did not read expected bytes: %ld expected, %d read (%s)",
                    flen, bytes_read, strerror(errno));
    }
    buffer[bytes_read] = '\0';  /* terminate the string */

/* close the stream */
    if (fclose(fp))
        SWISH_CROAK("error closing filehandle for %s: %s", filename,
                    strerror(errno));

    no_nulls(filename, buffer, (int)bytes_read);

    return buffer;

}

xmlChar *
swish_slurp_file(
    xmlChar *filename
)
{
    struct stat info;
/* fatal error, since we can't proceed */
    if (stat((char *)filename, &info)) {
        SWISH_CROAK("Can't stat %s: %s\n", filename, strerror(errno));
    }
    return swish_slurp_file_len(filename, info.st_size);

}

boolean
swish_file_exists(
    xmlChar *filename
)
{
    struct stat info;
    if (stat((char *)filename, &info)) {
        return 0;
    }
    return 1;
}