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Hands-on Lab·LPIC-1

The filters that process text streams

Objective 103.2 lists its commands by name and expects you to know what each one does. This guide runs them on one five-line file: selecting columns, ordering and counting, the small utilities, joining two files, and reshaping whitespace - with the two order dependencies that turn a correct-looking pipeline into a wrong answer.

101: GNU and Unix Commands Guide 26 of 33 Beginner

One host. Every command here is in coreutils and behaves identically on the RPM family.
Server NameIP AddressOSRolesCPURAMHDD
LPIC1-A01192.168.0.76Ubuntu 26.04 LTSDebian-family host - dpkg and apt, which objective 102.4 names2 Core4 GB50 GB

This guide includes

Use this when you have a file and need an answer out of it without writing a script. This matters because two of these commands produce plausible wrong output when used alone: uniq only sees adjacent lines, and cut treats every single space as a delimiter.

Before you start

  1. The files this guide works on

  2. Selecting columns, and where cut gives up

  3. Ordering, and counting what is there

  4. The small ones the objective names

  5. Joining and reshaping

  6. Whitespace, width and bytes

  7. Putting the machine back

Official sources

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