NAME¶

readdir - directory input parser for gawk

SYNOPSIS¶

@load "readdir"

BEGIN { PROCINFO["readdir_override"] = any_value } # optional

DESCRIPTION¶

The readdir extension adds an input parser for directories.

When this extension is in use, instead of skipping directories named on the command line (or with getline), they are read, with each entry returned as a record.

The record consists of three fields separated by forward slash characters. The first two are the inode number and the filename, and the third field is a single letter indicating the type of the file: f for file, d for directory, b for a block device, c for a character device, p for a FIFO, l for a symbolic link, or s for a socket.

On systems where the directory entry contains the file type, the third field is filled in from that information. On systems without the file type information, the extension falls back to calling stat(2), in order to provide the information. Thus the third field should never be u (unknown).

Normally, when reading directories, you should set FS equal to "/". However, you may instead chose to create PROCINFO["readdir_override"] (with any value). If this element exists when the directory is opened, then the extension automatically sets the fields in each record for you.

By default, if a directory cannot be opened (due to permission problems, for example), gawk will exit. As with regular files, this situation can be handled using a BEGINFILE rule that checks ERRNO and prints an error or otherwise handles the problem.

EXAMPLE¶

@load "readdir"
...
BEGIN { FS = "/" }
{ print "file name is", $2 }

SEE ALSO¶

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

opendir(3), readdir(3), stat(2).

AUTHOR¶

Arnold Robbins, arnold@skeeve.com.

COPYING PERMISSIONS¶

Copyright © 2012, 2013, 2018, 2019, 2023 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 distributed 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 notice may be stated in a translation approved by the Foundation.