| .\" Copyright (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de) |
| .\" |
| .\" %%%LICENSE_START(VERBATIM) |
| .\" Permission is granted to make and distribute verbatim copies of this |
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| .\" preserved on all copies. |
| .\" |
| .\" Permission is granted to copy and distribute modified versions of this |
| .\" manual under the conditions for verbatim copying, provided that the |
| .\" entire resulting derived work is distributed under the terms of a |
| .\" permission notice identical to this one. |
| .\" |
| .\" Since the Linux kernel and libraries are constantly changing, this |
| .\" manual page may be incorrect or out-of-date. The author(s) assume no |
| .\" responsibility for errors or omissions, or for damages resulting from |
| .\" the use of the information contained herein. The author(s) may not |
| .\" have taken the same level of care in the production of this manual, |
| .\" which is licensed free of charge, as they might when working |
| .\" professionally. |
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| .\" Formatted or processed versions of this manual, if unaccompanied by |
| .\" the source, must acknowledge the copyright and authors of this work. |
| .\" %%%LICENSE_END |
| .\" |
| .\" Modified Wed Jul 28 11:12:26 1993 by Rik Faith (faith@cs.unc.edu) |
| .\" |
| .\" FIXME Probably all of the following should be documented: |
| .\" _PC_SYNC_IO, |
| .\" _PC_ASYNC_IO, |
| .\" _PC_PRIO_IO, |
| .\" _PC_SOCK_MAXBUF, |
| .\" _PC_FILESIZEBITS, |
| .\" _PC_REC_INCR_XFER_SIZE, |
| .\" _PC_REC_MAX_XFER_SIZE, |
| .\" _PC_REC_MIN_XFER_SIZE, |
| .\" _PC_REC_XFER_ALIGN, |
| .\" _PC_ALLOC_SIZE_MIN, |
| .\" _PC_SYMLINK_MAX, |
| .\" _PC_2_SYMLINKS |
| .\" |
| .TH FPATHCONF 3 2015-08-08 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| fpathconf, pathconf \- get configuration values for files |
| .SH SYNOPSIS |
| .nf |
| .B #include <unistd.h> |
| .sp |
| .BI "long fpathconf(int " fd ", int " name ); |
| .br |
| .BI "long pathconf(const char *" path ", int " name ); |
| .fi |
| .SH DESCRIPTION |
| .BR fpathconf () |
| gets a value for the configuration option |
| .I name |
| for the open file descriptor |
| .IR fd . |
| .PP |
| .BR pathconf () |
| gets a value for configuration option |
| .I name |
| for the filename |
| .IR path . |
| .PP |
| The corresponding macros defined in |
| .I <unistd.h> |
| are minimum values; if an application wants to take advantage of values |
| which may change, a call to |
| .BR fpathconf () |
| or |
| .BR pathconf () |
| can be made, which may yield more liberal results. |
| .PP |
| Setting |
| .I name |
| equal to one of the following constants returns the following |
| configuration options: |
| .TP |
| .B _PC_LINK_MAX |
| returns the maximum number of links to the file. |
| If |
| .I fd |
| or |
| .I path |
| refer to a directory, then the value applies to the whole directory. |
| The corresponding macro is |
| .BR _POSIX_LINK_MAX . |
| .TP |
| .B _PC_MAX_CANON |
| returns the maximum length of a formatted input line, where |
| .I fd |
| or |
| .I path |
| must refer to a terminal. |
| The corresponding macro is |
| .BR _POSIX_MAX_CANON . |
| .TP |
| .B _PC_MAX_INPUT |
| returns the maximum length of an input line, where |
| .I fd |
| or |
| .I path |
| must refer to a terminal. |
| The corresponding macro is |
| .BR _POSIX_MAX_INPUT . |
| .TP |
| .B _PC_NAME_MAX |
| returns the maximum length of a filename in the directory |
| .I path |
| or |
| .IR fd |
| that the process is allowed to create. |
| The corresponding macro is |
| .BR _POSIX_NAME_MAX . |
| .TP |
| .B _PC_PATH_MAX |
| returns the maximum length of a relative pathname when |
| .I path |
| or |
| .I fd |
| is the current working directory. |
| The corresponding macro is |
| .BR _POSIX_PATH_MAX . |
| .TP |
| .B _PC_PIPE_BUF |
| returns the size of the pipe buffer, where |
| .I fd |
| must refer to a pipe or FIFO and |
| .I path |
| must refer to a FIFO. |
| The corresponding macro is |
| .BR _POSIX_PIPE_BUF . |
| .TP |
| .B _PC_CHOWN_RESTRICTED |
| returns nonzero if the |
| .BR chown (2) |
| call may not be used on this file. |
| If |
| .I fd |
| or |
| .I path |
| refer to a directory, then this applies to all files in that |
| directory. |
| The corresponding macro is |
| .BR _POSIX_CHOWN_RESTRICTED . |
| .TP |
| .B _PC_NO_TRUNC |
| returns nonzero if accessing filenames longer than |
| .B _POSIX_NAME_MAX |
| generates an error. |
| The corresponding macro is |
| .BR _POSIX_NO_TRUNC . |
| .TP |
| .B _PC_VDISABLE |
| returns nonzero if special character processing can be disabled, where |
| .I fd |
| or |
| .I path |
| must refer to a terminal. |
| .SH RETURN VALUE |
| The limit is returned, if one exists. |
| If the system does not have a |
| limit for the requested resource, \-1 is returned, and |
| .I errno |
| is unchanged. |
| If there is an error, \-1 is returned, and |
| .I errno |
| is set to reflect the nature of the error. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .TS |
| allbox; |
| lbw23 lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR fpathconf (), |
| .BR pathconf () |
| T} Thread safety MT-Safe |
| .TE |
| |
| .SH CONFORMING TO |
| POSIX.1-2001, POSIX.1-2008. |
| .SH NOTES |
| Files with name lengths longer than the value returned for |
| .I name |
| equal to |
| .B _PC_NAME_MAX |
| may exist in the given directory. |
| .PP |
| Some returned values may be huge; they are not suitable for allocating |
| memory. |
| .SH SEE ALSO |
| .BR getconf (1), |
| .BR open (2), |
| .BR statfs (2), |
| .BR confstr (3), |
| .BR sysconf (3) |