term% cat index.txt ACCESS(2) System Calls Manual ACCESS(2)
NAME
access - determine accessibility of file
SYNOPSIS
#include <u.h>
#include <libc.h>
int access(char *name, int mode)
DESCRIPTION
Access evaluates the given file name for accessibility. If mode&4 is
nonzero, read permission is expected; if mode&2, write permission; if
mode&1, execute permission. If mode==0, the file merely need exist.
In any case all directories leading to the file must permit searches.
Zero is returned if the desired access is permitted, -1 if not.
Only access for open is checked. A file may look executable, but
exec(2) will fail unless it is in proper format.
The include file defines AEXIST=0, AEXEC=1, AWRITE=2, and AREAD=4.
SOURCE
/sys/src/libc/9sys/access.c
SEE ALSO
stat(2)
DIAGNOSTICS
Sets errstr.
BUGS
Since file permissions are checked by the server and group information
is not known to the client, access must open the file to check permis‐
sions. (It calls stat(2) to check simple existence.)
ACCESS(2)