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