pathconf.3

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3 代码 · 共 94 行

.\" SCCSID: @(#)pathconf.3	2.3	8/10/87
.TH pathconf 3
.SH Name
pathconf, fpathconf \- get configurable pathname variables (POSIX)
.SH Syntax
.nf
.B #include <unistd.h>
.PP
.B long pathconf(\fIpath, name\fP)
.B char *\fIpath\fP;
.B int \fIname\fP;
.PP
.B long fpathconf(\fIfildes, name\fP)
.B int \fIfildes, name\fP;
.fi
.SH Description
The
.MS pathconf 3
and
.MS fpathconf 3
functions provide a method for the application to determine the current
value of a configurable limit or option that is associated with a file or
directory.
.NXR "pathconf subroutine"
.NXR "fpathconf subroutine"
.PP
For
.MS pathconf 3 ,
the
.IR path
argument points to the pathname of a file or directory. For
.MS fpathconf 3 ,
the
.IR fildes
argument is an open file descriptor.
.PP
The 
.IR name
argument represents the variable to be queried relative to that file or
directory. The following table
lists the variables which may be queried and the corresponding
value for the
.IR name
argument. The values for the
.IR name
argument are defined in the <unistd.h> header file.
.EX
Variable                    name Value

LINK_MAX                    _PC_LINK_MAX
MAX_CANON                   _PC_MAX_CANON
MAX_INPUT                   _PC_MAX_INPUT
NAME_MAX                    _PC_NAME_MAX
PATH_MAX                    _PC_PATH_MAX
PIPE_BUF                    _PC_PIPE_BUF
_POSIX_CHOWN_RESTRICTED     _PC_CHOWN_RESTRICTED
_POSIX_NO_TRUNC             _PC_NO_TRUNC
_POSIX_VDISABLE             _PC_VDISABLE
.EE
.SH Return Values
Upon successful completion, the
.MS pathconf 3
and
.MS fpathconf 3
functions return the current variable value for the file or directory.
.PP
If 
.IR name
is an invalid value,
.MS pathconf 3
and
.MS fpathconf 3
return \-1 and 
.I errno
is set to indicate the reason. If the variable corresponding to
.IR name
is not defined on the system,
.MS pathconf 3
and
.MS fpathconf 3
return \-1 without changing the value of
.I errno.
.SH Diagnostics
The
.MS pathconf 3
and
.MS fpathconf 3
functions fail if the following occurs:
.TP 15
[EINVAL]
The value of the \fIname\fP argument is invalid.
.SH See Also
<unistd.h>