ACCESS(2)
NAME
access − determine accessibility of a file
SYNOPSIS
int access (path, amode)
char ∗path;
int amode;
DESCRIPTION
Path points to a path name naming a file. Access checks the named file 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. The bit pattern contained in amode is constructed as follows:
04 read
02 write
01 execute (search)
00 check existence of file
Access to the file is denied if one or more of the following are true:
A component of the path prefix is not a directory. [ENOTDIR]
Read, write, or execute (search) permission is requested for a null path name. [ENOENT]
The named file does not exist. [ENOENT]
Search permission is denied on a component of the path prefix. [EACCES]
Write access is requested for a file on a read-only file system. [EROFS]
Write access is requested for a pure procedure (shared text) file that is being executed. [ETXTBSY]
Permission bits of the file mode do not permit the requested access. [EACCES]
Path points outside the process’s allocated address space. [EFAULT]
The owner of a file has permission checked with respect to the “owner” read, write, and execute mode bits, members of the file’s group other than the owner have permissions checked with respect to the “group” mode bits, and all others have permissions checked with respect to the “other” mode bits.
RETURN VALUE
If the requested access is permitted, a value of 0 is returned. Otherwise, a value of −1 is returned and errno is set to indicate the error.