filefuncs(3am) - man - phpMan

 


filefuncs(3am)
NAME SYNOPSIS DESCRIPTION NOTES BUGS EXAMPLE SEE ALSO AUTHOR COPYING PERMISSIONS
FILEFUNCS(3am)                        GNU Awk Extension Modules                       FILEFUNCS(3am)



NAME
       filefuncs - provide some file related functionality to gawk

SYNOPSIS
       @load "filefuncs"

       result = chdir("/some/directory")

       result = stat("/some/path", statdata [, follow])

       flags = or(FTS_PHYSICAL, ...)
       result = fts(pathlist, flags, filedata)

       result = statvfs("/some/path", fsdata)

DESCRIPTION
       The  filefuncs  extension  adds several functions that provide access to file-related facili‐
       ties.

   chdir()
       The chdir() function is a direct hook to the chdir(2) system call to change the  current  di‐
       rectory.   It  returns zero upon success or less than zero upon error.  In the latter case it
       updates ERRNO.

   stat()
       The stat() function provides a hook into the stat(2) system call.  It returns zero upon  suc‐
       cess or less than zero upon error.  In the latter case it updates ERRNO.  By default, it uses
       lstat(2).  However, if passed a third argument, it uses stat(2), instead.

       In all cases, it clears the statdata array.  When the call is successful,  stat()  fills  the
       statdata array with information retrieved from the filesystem, as follows:

       statdata["name"]
              The name of the file, equal to the first argument passed to stat().

       statdata["dev"]
              Corresponds to the st_dev field in the struct stat.

       statdata["ino"]
              Corresponds to the st_ino field in the struct stat.

       statdata["mode"]
              Corresponds to the st_mode field in the struct stat.

       statdata["nlink"]
              Corresponds to the st_nlink field in the struct stat.

       statdata["uid"]
              Corresponds to the st_uid field in the struct stat.

       statdata["gid"]
              Corresponds to the st_gid field in the struct stat.

       statdata["size"]
              Corresponds to the st_size field in the struct stat.

       statdata["atime"]
              Corresponds to the st_atime field in the struct stat.

       statdata["mtime"]
              Corresponds to the st_mtime field in the struct stat.

       statdata["ctime"]
              Corresponds to the st_ctime field in the struct stat.

       statdata["rdev"]
              Corresponds to the st_rdev field in the struct stat.  This element is only present for
              device files.

       statdata["major"]
              Corresponds to the st_major field in the struct stat.  This element  is  only  present
              for device files.

       statdata["minor"]
              Corresponds  to  the  st_minor field in the struct stat.  This element is only present
              for device files.

       statdata["blksize"]
              Corresponds to the st_blksize field in the struct stat, if this field  is  present  on
              your system.  (It is present on all modern systems that we know of.)

       statdata["pmode"]
              A  human-readable  version  of the mode value, such as printed by ls(1).  For example,
              "-rwxr-xr-x".

       statdata["linkval"]
              If the named file is a symbolic link, this element will exist and  its  value  is  the
              value of the symbolic link (where the symbolic link points to).

       statdata["type"]
              The  type  of the file as a string. One of "file", "blockdev", "chardev", "directory",
              "socket", "fifo", "symlink", "door", or "unknown".  Not all systems support  all  file
              types.

   fts()
       The  fts() function provides a hook to the fts(3) set of routines for traversing file hierar‐
       chies.  Instead of returning data about one file at a time in a stream, it fills in a  multi-
       dimensional  array with data about each file and directory encountered in the requested hier‐
       archies.

       The arguments are as follows:

       pathlist
              An array of filenames.  The element values are used; the index values are ignored.

       flags  This should be the bitwise OR of one or more of the following predefined flag  values.
              At  least one of FTS_LOGICAL or FTS_PHYSICAL must be provided; otherwise fts() returns
              an error value and sets ERRNO.

              FTS_LOGICAL
                     Do a ``logical'' file traversal, where the information returned for a  symbolic
                     link  refers  to the linked-to file, and not to the symbolic link itself.  This
                     flag is mutually exclusive with FTS_PHYSICAL.

              FTS_PHYSICAL
                     Do a ``physical'' file traversal, where the information returned for a symbolic
                     link  refers to the symbolic link itself.  This flag is mutually exclusive with
                     FTS_LOGICAL.

              FTS_NOCHDIR
                     As a performance optimization, the fts(3) routines  change  directory  as  they
                     traverse a file hierarchy.  This flag disables that optimization.

              FTS_COMFOLLOW
                     Immediately  follow a symbolic link named in pathlist, whether or not FTS_LOGI‐‐
                     CAL is set.

              FTS_SEEDOT
                     By default, the fts(3) routines do not return entries  for  ``.''  and  ``..''.
                     This  option causes entries for ``..'' to also be included.  (The AWK extension
                     always includes an entry for ``.'', see below.)

              FTS_XDEV
                     During a traversal, do not cross onto a different mounted filesystem.

              FTS_SKIP
                     When set, causes top level directories to not be descended into.

       filedata
              The filedata array is first cleared.  Then, fts() creates an element in  filedata  for
              every  element  in  pathlist.  The index is the name of the directory or file given in
              pathlist.  The element for this index is itself an array.  There are two cases.

              The path is a file.
                     In this case, the array contains two or three elements:

                     "path" The full path to this file, starting from the ``root'' that was given in
                            the pathlist array.

                     "stat" This element is itself an array, containing the same information as pro‐
                            vided by the stat() function described earlier for  its  statdata  argu‐
                            ment.  The element may not be present if stat(2) for the file failed.

                     "error"
                            If  some  kind  of error was encountered, the array will also contain an
                            element named "error", which is a string describing the error.

              The path is a directory.
                     In this case, the array contains one element for each entry in  the  directory.
                     If  an  entry  is a file, that element is as for files, just described.  If the
                     entry is a directory, that element is (recursively), an  array  describing  the
                     subdirectory.  If FTS_SEEDOT was provided in the flags, then there will also be
                     an element named "..".  This element will be an array containing  the  data  as
                     provided by stat().

                     In  addition,  there will be an element whose index is ".".  This element is an
                     array containing the same two or three elements as for a file: "path",  "stat",
                     and "error".

       The fts() function returns 0 if there were no errors. Otherwise it returns -1.

   statvfs()
       The statvfs() function provides a hook into the statvfs(2) system call on systems that supply
       this system call.  It returns zero upon success or less than zero upon error.  In the  latter
       case it updates ERRNO.

       When  the  call  is  successful,  statvfs() fills the fsdata array with information retrieved
       about the filesystem, as follows:

       fsdata["bsize"]
              Corresponds to the bsize member in the struct statvfs.

       fsdata["frsize"]
              Corresponds to the f_frsize member in the struct statvfs.

       fsdata["blocks"]
              Corresponds to the f_blocks member in the struct statvfs.

       fsdata["bfree"]
              Corresponds to the f_bfree member in the struct statvfs.

       fsdata["bavail"]
              Corresponds to the f_bavail member in the struct statvfs.

       fsdata["files"]
              Corresponds to the f_files member in the struct statvfs.

       fsdata["ffree"]
              Corresponds to the f_ffree member in the struct statvfs.

       fsdata["favail"]
              Corresponds to the f_favail member in the struct statvfs.

       fsdata["fsid"]
              Corresponds to the f_fsid member in the struct statvfs.  This member is not  available
              on all systems.

       fsdata["flag"]
              Corresponds to the f_flag member in the struct statvfs.

       fsdata["namemax"]
              Corresponds to the f_namemax member in the struct statvfs.

NOTES
       The AWK fts() extension does not exactly mimic the interface of the fts(3) routines, choosing
       instead to provide an interface that is based on associative arrays,  which  should  be  more
       comfortable  to  use  from  an AWK program.  This includes the lack of a comparison function,
       since gawk already provides powerful array sorting facilities.  While an fts_read()-like  in‐
       terface  could have been provided, this felt less natural than simply creating a multi-dimen‐
       sional array to represent the file hierarchy and its information.

       Nothing prevents AWK code from changing the predefined FTS_xx values, but doing so may  cause
       strange results when the changed values are passed to fts().

BUGS
       There are many more file-related functions for which AWK interfaces would be desirable.

       It's not clear why I thought adding FTS_SKIP was a good idea.

EXAMPLE
       See test/fts.awk in the gawk distribution for an example.

SEE ALSO
       GAWK:  Effective  AWK  Programming, fnmatch(3am), fork(3am), inplace(3am), ordchr(3am), readdir(3am), readfile(3am), revoutput(3am), rwarray(3am), time(3am).

       chdir(2), fts(3), stat(2), statvfs(2).

AUTHOR
       Arnold Robbins, arnold AT skeeve.com.

COPYING PERMISSIONS
       Copyright © 2012, 2013, 2018, 2019, Free Software Foundation, Inc.

       Permission is granted to make and distribute verbatim copies of this manual page provided the
       copyright notice and this permission notice are preserved on all copies.

       Permission  is granted to copy and distribute modified versions of this manual page under the
       conditions for verbatim copying, provided that the entire resulting derived work is  distrib‐
       uted under the terms of a permission notice identical to this one.

       Permission  is  granted  to copy and distribute translations of this manual page into another
       language, under the above conditions for modified versions, except that this  permission  no‐
       tice may be stated in a translation approved by the Foundation.



Free Software Foundation                     Feb 21 2018                              FILEFUNCS(3am)

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