svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.
access(2)
access(2) System Calls access(2)
NAME
access, euidaccess, faccessat - determine accessibility of a file
SYNOPSIS
#include <unistd.h>
#include <sys/fcntl.h>
int access(const char *path, int amode);
int euidaccess(const char *path, int amode);
int faccessat(int fd, const char *path, int amode, int flag);
DESCRIPTION
The access() function checks the file named by the pathname pointed to
by the path argument for accessibility according to the bit pattern
contained in amode, using the real user ID in place of the effective
user ID and the real group ID in place of the effective group ID. This
allows a setuid process to verify that the user running it would have
had permission to access this file.
The value of amode is either the bitwise inclusive OR of the access
permissions to be checked (R_OK, W_OK, X_OK) or the existence test,
F_OK.
These constants are defined in <unistd.h> as follows:
R_OK Test for read permission.
W_OK Test for write permission.
X_OK Test for execute or search permission.
F_OK Check existence of file
See the "File Access Permissions" section of Intro(2) for additional
information. As described there, access may be permitted by the permis‐
sion bits in the file mode, entries in an Access Control List, or priv‐
ileges currently asserted for the process.
If any access permissions are to be checked, each will be checked indi‐
vidually, as described in Intro(2). If the process has appropriate
privileges, an implementation may indicate success for X_OK even if
none of the execute file permission bits are set.
The faccessat() function is equivalent to the access() function, except
in the case where path specifies a relative path. In this case the file
whose accessibility is to be determined is located relative to the di‐
rectory associated with the file descriptor fd instead of the current
working directory.
If faccessat() is passed in the fd parameter the special value AT_FD‐
CWD, defined in <fcntl.h>, the current working directory is used and
the behavior is identical to a call to access().
Values for flag are constructed by a bitwise-inclusive OR of flags from
the following list, defined in <fcntl.h>:
AT_EACCESS The checks for accessibility are performed using the ef‐
fective user and group IDs instead of the real user and
group ID as required in a call to access().
The euidaccess() function is equivalent to the faccessat() function
with an fd of AT_FDCWD and a flag of AT_EACCESS, so that it checks for
access using the effective user ID and the effective group ID.
RETURN VALUES
If the requested access is permitted, access(), euidaccess(), and fac‐
cessat() succeed and return 0. Otherwise, −1 is returned and errno is
set to indicate the error.
ERRORS
The access(), euidaccess(), and faccessat() functions will fail if:
EACCES Permissions of the file do not permit the requested ac‐
cess, or search permission is denied on a component of
the path prefix.
EFAULT The path argument points to an illegal address.
EINTR A signal was caught during the function.
ELOOP Too many symbolic links were encountered in resolving
path, or loop exists in symbolic links encountered dur‐
ing resolution of the path argument.
ENAMETOOLONG The length of the path argument exceeds {PATH_MAX}, or
a pathname component is longer than {NAME_MAX} while
_POSIX_NO_TRUNC is in effect.
ENOENT A component of path does not name an existing file or
path is an empty string.
ENOLINK The path argument points to a remote machine and the
link to that machine is no longer active.
ENOTDIR A component of the path prefix is not a directory.
ENXIO The path argument points to a character or block device
special file and the corresponding device has been re‐
tired by the fault management framework.
EROFS Write access is requested for a file on a read-only
file system.
The faccessat() function will fail if:
EBADF The path argument does not specify an absolute path and the fd
argument is neither AT_FDCWD nor a valid file descriptor open
for reading or searching.
The access(), euidaccess(), and faccessat() functions may fail if:
EINVAL The value of the amode argument is invalid.
ENAMETOOLONG Pathname resolution of a symbolic link produced an in‐
termediate result whose length exceeds {PATH_MAX}.
ETXTBSY Write access is requested for a pure procedure (shared
text) file that is being executed.
The faccessat() function may fail if:
EINVAL The value of the flag argument is not valid.
ENOTDIR The path argument is not an absolute path and fd is neither
AT_FDCWD nor a file descriptor associated with a directory.
USAGE
Additional values of amode other than the set defined in the descrip‐
tion might be valid, for example, if a system has extended access con‐
trols.
The purpose of the faccessat() function is to enable the checking of
the accessibility of files in directories other than the current work‐
ing directory without exposure to race conditions. Any part of the path
of a file could be changed in parallel to a call to access(), resulting
in unspecified behavior. By opening a file descriptor for the target
directory and using the faccessat() function, it can be guaranteed that
the file tested for accessibility is located relative to the desired
directory.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRIBUTE TYPEAT‐
TRIBUTE VALUE _ Interface StabilityCommitted _ MT-LevelAsync-Signal-
Safe _ StandardSee below.
Standard
See standards(7) for descriptions of the following standards:
tab() box; cw(2.2i) |cw(3.3i) lw(2.2i) |lw(3.3i) INTERFACESAPPLICABLE
STANDARDS _ access()T{
POSIX.1-1990 through 2008,
SUS through SUSv4,
XPG1 through XPG7
T} _ faccessat()T{
SUSv4,
XPG7
T} _ euidaccess()None
SEE ALSO
chmod(2), Intro(2), stat(2), acl(7), attributes(7), standards(7)
HISTORY
The euidaccess() function was added to Oracle Solaris in Solaris
11.4.0.
The faccessat() function was added to Oracle Solaris in Solaris 11.0.0.
The access() function has been included in all Sun and Oracle releases
of Solaris.
Oracle Solaris 11.4 30 Jan 2023 access(2)