isc/unix/file.c

	file.c revision a548a3c20cf520a61b7e6c6332de51bae2314e45


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/*
 * Copyright (C) 2000, 2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: file.c,v 1.37 2001/07/16 17:26:44 gson Exp $ */

#include <config.h>

#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <time.h>       /* Required for utimes on some platforms. */
#include <unistd.h>     /* Required for mkstemp on NetBSD. */

#include <sys/stat.h>
#include <sys/time.h>

#include <isc/dir.h>
#include <isc/file.h>
#include <isc/string.h>
#include <isc/time.h>
#include <isc/util.h>

#include "errno2result.h"

/*
 * XXXDCL As the API for accessing file statistics undoubtedly gets expanded,
 * it might be good to provide a mechanism that allows for the results
 * of a previous stat() to be used again without having to do another stat,
 * such as perl's mechanism of using "_" in place of a file name to indicate
 * that the results of the last stat should be used.  But then you get into
 * annoying MP issues.   BTW, Win32 has stat().
 */
static isc_result_t
file_stats(const char *file, struct stat *stats) {
    isc_result_t result = ISC_R_SUCCESS;

    REQUIRE(file != NULL);
    REQUIRE(stats != NULL);

    if (stat(file, stats) != 0)
        result = isc__errno2result(errno);

    return (result);
}

isc_result_t
isc_file_getmodtime(const char *file, isc_time_t *time) {
    isc_result_t result;
    struct stat stats;

    REQUIRE(file != NULL);
    REQUIRE(time != NULL);

    result = file_stats(file, &stats);

    if (result == ISC_R_SUCCESS)
        /*
         * XXXDCL some operating systems provide nanoseconds, too,
         * such as BSD/OS via st_mtimespec.
         */
        isc_time_set(time, stats.st_mtime, 0);

    return (result);
}

isc_result_t
isc_file_settime(const char *file, isc_time_t *time) {
    struct timeval times[2];

    REQUIRE(file != NULL && time != NULL);

    /*
     * tv_sec is at least a 32 bit quantity on all platforms we're
     * dealing with, but it is signed on most (all?) of them,
     * so we need to make sure the high bit isn't set.  This unfortunately
     * loses when either:
     *   * tv_sec becomes a signed 64 bit integer but long is 32 bits
     *  and isc_time_seconds > LONG_MAX, or
     *   * isc_time_seconds is changed to be > 32 bits but long is 32 bits
     *      and isc_time_seconds has at least 33 significant bits.
     */
    times[0].tv_sec = times[1].tv_sec = (long)isc_time_seconds(time);

    /*
     * Here is the real check for the high bit being set.
     */
    if ((times[0].tv_sec &
         (1ULL << (sizeof(times[0].tv_sec) * CHAR_BIT - 1))) != 0)
        return (ISC_R_RANGE);

    /*
     * isc_time_nanoseconds guarantees a value that divided by 1000 will
     * fit into the minimum possible size tv_usec field.  Unfortunately,
     * we don't know what that type is so can't cast directly ... but
     * we can at least cast to signed so the IRIX compiler shuts up.
     */
    times[0].tv_usec = times[1].tv_usec =
        (isc_int32_t)(isc_time_nanoseconds(time) / 1000);

    if (utimes(file, times) < 0)
        return (isc__errno2result(errno));

    return (ISC_R_SUCCESS);

}

#undef TEMPLATE
#define TEMPLATE "tmp-XXXXXXXXXX" /* 14 characters. */

isc_result_t
isc_file_mktemplate(const char *path, char *buf, size_t buflen) {
    return (isc_file_template(path, TEMPLATE, buf, buflen));
}

isc_result_t
isc_file_template(const char *path, const char *templet, char *buf,
            size_t buflen) {
    char *s;

    REQUIRE(path != NULL);
    REQUIRE(templet != NULL);
    REQUIRE(buf != NULL);

    s = strrchr(templet, '/');
    if (s != NULL)
        templet = s + 1;

    s = strrchr(path, '/');

    if (s != NULL) {
        if ((s - path + 1 + strlen(templet) + 1) > buflen)
            return (ISC_R_NOSPACE);

        strncpy(buf, path, s - path + 1);
        buf[s - path + 1] = '\0';
        strcat(buf, templet);
    } else {
        if ((strlen(templet) + 1) > buflen)
            return (ISC_R_NOSPACE);

        strcpy(buf, templet);
    }

    return (ISC_R_SUCCESS);
}

isc_result_t
isc_file_renameunique(const char *file, char *templet) {
    int fd = -1;
    int res = 0;
    isc_result_t result = ISC_R_SUCCESS;

    REQUIRE(file != NULL);
    REQUIRE(templet != NULL);

    fd = mkstemp(templet);
    if (fd == -1) {
        result = isc__errno2result(errno);
    }
    if (result == ISC_R_SUCCESS) {
        res = rename(file, templet);
        if (res != 0) {
            result = isc__errno2result(errno);
            (void)unlink(templet);
        }
    }
    if (fd != -1)
        close(fd);
    return (result);
}

isc_result_t
isc_file_openunique(char *templet, FILE **fp) {
    int fd;
    FILE *f;
    isc_result_t result = ISC_R_SUCCESS;

    REQUIRE(templet != NULL);
    REQUIRE(fp != NULL && *fp == NULL);

    /*
     * Win32 does not have mkstemp.
     */
    fd = mkstemp(templet);

    if (fd == -1)
        result = isc__errno2result(errno);
    if (result == ISC_R_SUCCESS) {
        f = fdopen(fd, "w+");
        if (f == NULL) {
            result = isc__errno2result(errno);
            (void)remove(templet);
            (void)close(fd);

        } else
            *fp = f;
    }

    return (result);
}

isc_result_t
isc_file_remove(const char *filename) {
    int r;

    REQUIRE(filename != NULL);

    r = unlink(filename);
    if (r == 0)
        return (ISC_R_SUCCESS);
    else
        return (isc__errno2result(errno));
}

isc_result_t
isc_file_rename(const char *oldname, const char *newname) {
    int r;

    REQUIRE(oldname != NULL);
    REQUIRE(newname != NULL);

    r = rename(oldname, newname);
    if (r == 0)
        return (ISC_R_SUCCESS);
    else
        return (isc__errno2result(errno));
}

isc_boolean_t
isc_file_exists(const char *pathname) {
    struct stat stats;

    REQUIRE(pathname != NULL);

    return (ISC_TF(file_stats(pathname, &stats) == ISC_R_SUCCESS));
}

isc_boolean_t
isc_file_isabsolute(const char *filename) {
    REQUIRE(filename != NULL);
    return (ISC_TF(filename[0] == '/'));
}

isc_boolean_t
isc_file_iscurrentdir(const char *filename) {
    REQUIRE(filename != NULL);
    return (ISC_TF(filename[0] == '.' && filename[1] == '\0'));
}

const char *
isc_file_basename(const char *filename) {
    char *s;

    REQUIRE(filename != NULL);

    s = strrchr(filename, '/');
    if (s == NULL)
        return (filename);

    return (s + 1);
}

isc_result_t
isc_file_progname(const char *filename, char *buf, size_t buflen) {
    const char *base;
    size_t len;

    REQUIRE(filename != NULL);
    REQUIRE(buf != NULL);

    base = isc_file_basename(filename);
    len = strlen(base) + 1;

    if (len > buflen)
        return (ISC_R_NOSPACE);
    memcpy(buf, base, len);

    return (ISC_R_SUCCESS);
}

isc_result_t
isc_file_absolutepath(const char *filename, char *path, size_t pathlen) {
    isc_result_t result;
    result = isc_dir_current(path, pathlen, ISC_TRUE);
    if (result != ISC_R_SUCCESS)
        return (result);
    if (strlen(path) + strlen(filename) + 1 > pathlen)
        return (ISC_R_NOSPACE);
    strcat(path, filename);
    return (ISC_R_SUCCESS);
}