pathconf

FPATHCONF(3)               Linux Programmer's Manual              FPATHCONF(3)



NAME
       fpathconf, pathconf - get configuration values for files

SYNOPSIS
       #include <unistd.h>

       long fpathconf(int filedes, int name);
       long pathconf(char *path, int name);

DESCRIPTION
       fpathconf() gets a value for the configuration option name for the open
       file descriptor filedes.

       pathconf() gets a value for configuration option name for the file name
       path.

       The  corresponding  macros defined in <unistd.h> are minimum values; if
       an application wants to take advantage of values which  may  change,  a
       call  to  fpathconf()  or  pathconf() can be made, which may yield more
       liberal results.

       Setting name equal to one of the following constants returns  the  fol-
       lowing configuration options:

       _PC_LINK_MAX
              returns  the maximum number of links to the file.  If filedes or
              path refer to a directory, then the value applies to  the  whole
              directory.  The corresponding macro is _POSIX_LINK_MAX.

       _PC_MAX_CANON
              returns  the  maximum  length  of  a formatted input line, where
              filedes or path must refer to  a  terminal.   The  corresponding
              macro is _POSIX_MAX_CANON.

       _PC_MAX_INPUT
              returns  the  maximum  length of an input line, where filedes or
              path must refer to  a  terminal.   The  corresponding  macro  is
              _POSIX_MAX_INPUT.

       _PC_NAME_MAX
              returns  the  maximum length of a filename in the directory path
              or filedes.  the process is allowed to create.  The  correspond-
              ing macro is _POSIX_NAME_MAX.

       _PC_PATH_MAX
              returns  the  maximum length of a relative pathname when path or
              filedes is the current  working  directory.   The  corresponding
              macro is _POSIX_PATH_MAX.

       _PC_PIPE_BUF
              returns the size of the pipe buffer, where filedes must refer to
              a pipe or FIFO and path must refer to a FIFO. The  corresponding
              macro is _POSIX_PIPE_BUF.

       _PC_CHOWN_RESTRICTED
              returns  nonzero  if  the  chown(2) call may not be used on this
              file.  If filedes or  path  refer  to  a  directory,  then  this
              applies to all files in that directory.  The corresponding macro
              is _POSIX_CHOWN_RESTRICTED.

       _PC_NO_TRUNC
              returns   nonzero   if   accessing   filenames    longer    than
              _POSIX_NAME_MAX  generates an error.  The corresponding macro is
              _POSIX_NO_TRUNC.

       _PC_VDISABLE
              returns nonzero if special character processing can be disabled,
              where filedes or path must refer to a terminal.

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  errno  is
       unchanged.   If  there is an error, -1 is returned, and errno is set to
       reflect the nature of the error.

CONFORMING TO
       POSIX.1

NOTES
       Files with name lengths longer than the value returned for  name  equal
       to _PC_NAME_MAX may exist in the given directory.

       Some  returned values may be huge; they are not suitable for allocating
       memory.

SEE ALSO
       getconf(1), statfs(2), open(2), sysconf(3)



GNU                               1993-04-04                      FPATHCONF(3)