Dbcol (1) Linux Manual Page

dbcol – select columns from an Fsdb file

Synopsis

dbcol [-v] [-e -] [column…]

Description

Select one or more columns from the input database. If a value is given for empty columns with the -e option, then any named columns which don’t exist will be created. Otherwise, non-existent columns are an error.

Note: a safer way to create columns is dbcolcreate.

Options

-r or –relaxed-errors: Relaxed error checking: ignore columns that aren’t there.
-v or –invert-match: Output all columns except those listed (like grep -v).
-e EmptyValue or –empty: Specify the value newly created columns get.

and the standard fsdb options:

-d: Enable debugging output.
-i or –input InputSource: Read from InputSource, typically a file, or – for standard input, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.
-o or –output OutputDestination: Write to OutputDestination, typically a file, or – for standard output, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.
–autorun or –noautorun: By default, programs process automatically, but Fsdb::Filter objects in Perl do not run until you invoke the run() method. The "–(no)autorun" option controls that behavior within Perl.
–help: Show help.
–man: Show full manual.

Sample Usage

Input:

 #fsdb account passwd uid gid fullname homedir shell

 johnh * 2274 134 John_Heidemann /home/johnh /bin/bash

 greg * 2275 134 Greg_Johnson /home/greg /bin/bash

 root * 0 0 Root /root /bin/bash

 # this is a simple database

Command:

 cat DATA/passwd.fsdb account | dbcol account

Output:

 #fsdb account

 johnh

 greg

 root

 # this is a simple database

 # | dbcol account

AUTHOR and COPYRIGHT

This program is distributed under terms of the GNU general public license, version 2. See the file COPYING with the distribution for details.

dbcol (1) Linux Manual Page