| .TH ACCESS 3 |
| .SH NAME |
| access \- determine accessibility of file |
| .SH SYNOPSIS |
| .B #include <u.h> |
| .br |
| .B #include <libc.h> |
| .PP |
| .B |
| int access(char *name, int mode) |
| .SH DESCRIPTION |
| .I Access |
| evaluates the given |
| file |
| .I name |
| for accessibility. |
| If \fImode\fL&4\fR |
| is nonzero, |
| read permission is expected; |
| if \fImode\fL&2\fR, |
| write permission; |
| if \fImode\fL&1\fR, |
| execute permission. |
| If \fImode\fL==0\fR, |
| 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. |
| .PP |
| Only access for open is checked. |
| A file may look executable, but |
| .IR exec (3) |
| will fail unless it is in proper format. |
| .PP |
| The include file |
| .F <libc.h> |
| defines |
| .BR AEXIST =0, |
| .BR AEXEC =1, |
| .BR AWRITE =2, |
| and |
| .BR AREAD =4. |
| .PP |
| .SH SOURCE |
| .B /usr/local/plan9/src/libc/9sys/access.c |
| .SH SEE ALSO |
| .IR stat (3) |
| .SH DIAGNOSTICS |
| Sets |
| .IR errstr . |
| .SH BUGS |
| Since file permissions are checked by the server and group information |
| is not known to the client, |
| .I access |
| must open the file to check permissions. |
| (It calls |
| .IR stat (3) |
| to check simple existence.) |
