dbcol man 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

See Also

dbcolcreate(1), Fsdb(3)

Info

2016-11-30 perl v5.24.0 User Contributed Perl Documentation