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openmpi/opal/util/opal_getcwd.c

103 строки
2.8 KiB
C
Исходник Обычный вид История

/*
* Copyright (c) 2007 Cisco Systems, Inc. All rights reserved.
* $COPYRIGHT$
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*
* Additional copyrights may follow
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*
* $HEADER$
*/
#include "opal_config.h"
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include "opal/util/basename.h"
#include "opal/util/opal_getcwd.h"
#include "opal/constants.h"
/*
* Use $PWD instead of getcwd() a) if $PWD exists and b) is a valid
* synonym for the results from getcwd(). If both of these conditions
* are not met, just fall back and use the results of getcwd().
*/
int opal_getcwd(char *buf, size_t size)
{
char cwd[OPAL_PATH_MAX];
char *pwd = getenv("PWD");
struct stat a, b;
char *shortened;
/* Bozo checks (e.g., if someone accidentally passed -1 to the
unsigned "size" param) */
if (NULL == buf || size > INT_MAX) {
return OPAL_ERR_BAD_PARAM;
}
/* Call getcwd() to get a baseline result */
if (NULL == getcwd(cwd, sizeof(cwd))) {
return OPAL_ERR_IN_ERRNO;
}
#if !defined(HAVE_SYS_STAT_H)
/* If we don't have stat(), then we can't tell if the $PWD and cwd
are the same, so just fall back to getcwd(). */
pwd = cwd;
#else
if (NULL == pwd) {
pwd = cwd;
} else {
/* If the two are not the same value, figure out if they are
pointing to the same place */
if (0 != strcmp(pwd, cwd)) {
/* If we can't stat() what getcwd() gave us, give up */
if (0 != stat(cwd, &a)) {
return OPAL_ERR_IN_ERRNO;
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}
/* If we can't stat() $PWD, then $PWD could just be stale
-- so ignore it. */
else if (0 != stat(pwd, &b)) {
pwd = cwd;
}
/* Otherwise, we successfully stat()'ed them both, so
compare. If either the device or inode is not the
same, then fallback to getcwd(). */
else {
if (a.st_dev != b.st_dev || a.st_ino != b.st_ino) {
pwd = cwd;
}
}
}
}
#endif
/* If we got here, pwd is pointing to the result that we want to
give. Ensure the user's buffer is long enough. If it is, copy
in the value and be done. */
if (strlen(pwd) > size) {
/* if it isn't big enough, give them as much
* of the basename as possible
*/
shortened = opal_basename(pwd);
strncpy(buf, shortened, size);
free(shortened);
/* ensure it is null terminated */
buf[size-1] = '\0';
/* indicate that it isn't the full path */
return OPAL_ERR_TEMP_OUT_OF_RESOURCE;
}
strncpy(buf, pwd, size);
return OPAL_SUCCESS;
}