dbcol - select columns from an Fsdb file

NOTE: this page was directly converted from the perl FSDB manual pages from FSDB version 3.1

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).

-a or –all

Output all columns, in addition to those listed. (Thus -a foo will move column foo to the first column.)

-e EmptyValue or –empty

Specify the value newly created columns get.

–saveoutput $OUT_REF

Save output writer (for integration with other fsdb filters).

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.

--header H

Use H as the full Fsdb header, rather than reading a header from then input.

--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

SEE ALSO

dbcolcreate (1), Fsdb (3)