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Diffstat (limited to 'lib/libc/sys/pathconf.2')
-rw-r--r-- | lib/libc/sys/pathconf.2 | 163 |
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diff --git a/lib/libc/sys/pathconf.2 b/lib/libc/sys/pathconf.2 new file mode 100644 index 0000000..1b4fbc4 --- /dev/null +++ b/lib/libc/sys/pathconf.2 @@ -0,0 +1,163 @@ +.\" Copyright (c) 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)pathconf.2 8.1 (Berkeley) 6/4/93 +.\" +.Dd June 4, 1993 +.Dt PATHCONF 2 +.Os BSD 4 +.Sh NAME +.Nm pathconf , +.Nm fpathconf +.Nd get configurable pathname variables +.Sh SYNOPSIS +.Fd #include <unistd.h> +.Ft long +.Fn pathconf "const char *path" "int name" +.Ft long +.Fn fpathconf "int fd" "int name" +.Sh DESCRIPTION +.Pp +The +.Fn pathconf +and +.Fn fpathconf +functions provides a method for applications to determine the current +value of a configurable system limit or option variable associated +with a pathname or file descriptor. +.Pp +For +.Nm pathconf , +the +.Fa path +argument is the name of a file or directory. +For +.Nm fpathconf , +the +.Fa fd +argument is an open file descriptor. +The +.Fa name +argument specifies the system variable to be queried. +Symbolic constants for each name value are found in the include file +.Li <unistd.h> . +.Pp +The available values are as follows: +.Pp +.Bl -tag -width "123456" +.Pp +.It Li _PC_LINK_MAX +The maximum file link count. +.It Li _PC_MAX_CANON +The maximum number of bytes in terminal canonical input line. +.It Li _PC_MAX_INPUT +The minimum maximum number of bytes for which space is available in +a terminal input queue. +.It Li _PC_NAME_MAX +The maximum number of bytes in a file name. +.It Li _PC_PATH_MAX +The maximum number of bytes in a pathname. +.It Li _PC_PIPE_BUF +The maximum number of bytes which will be written atomically to a pipe. +.It Li _PC_CHOWN_RESTRICTED +Return 1 if appropriate privileges are required for the +.Xr chown 2 +system call, otherwise 0. +.It Li _PC_NO_TRUNC +Return 1 if file names longer than KERN_NAME_MAX are truncated. +.It Li _PC_VDISABLE +Returns the terminal character disabling value. +.El +.Sh RETURN VALUES +If the call to +.Nm pathconf +or +.Nm fpathconf +is not successful, \-1 is returned and +.Va errno +is set appropriately. +Otherwise, if the variable is associated with functionality that does +not have a limit in the system, \-1 is returned and +.Va errno +is not modified. +Otherwise, the current variable value is returned. +.Sh ERRORS +If any of the following conditions occur, the +.Nm pathconf +and +.Nm fpathconf +functions shall return -1 and set +.Va errno +to the corresponding value. +.Bl -tag -width Er +.It Bq Er EINVAL +The value of the +.Fa name +argument is invalid. +.It Bq Er EINVAL +The implementation does not support an association of the variable +name with the associated file. +.El +.Fn Pathconf +will fail if: +.Bl -tag -width ENAMETOOLONGAA +.It Bq Er ENOTDIR +A component of the path prefix is not a directory. +.It Bq Er ENAMETOOLONG +A component of a pathname exceeded 255 characters, +or an entire path name exceeded 1023 characters. +.It Bq Er ENOENT +The named file does not exist. +.It Bq Er EACCES +Search permission is denied for a component of the path prefix. +.It Bq Er ELOOP +Too many symbolic links were encountered in translating the pathname. +.It Bq Er EIO +An I/O error occurred while reading from or writing to the file system. +.El +.Pp +.Bl -tag -width [EFAULT] +.Fn Fpathconf +will fail if: +.It Bq Er EBADF +.Fa fd +is not a valid open file descriptor. +.It Bq Er EIO +An I/O error occurred while reading from or writing to the file system. +.El +.Sh SEE ALSO +.Xr sysctl 3 +.Sh HISTORY +The +.Nm pathconf +and +.Nm fpathconf +functions first appeared in 4.4BSD. |