Goal: Introduce how to pipe the output of one command into the input of another, and how to redirect the output of a command into a file.

Output Redirection and Pipes

Redirection of output: > vs >>
- A redirect sends a channel of output to a file.
- A channel refers to standard input/output as well as standard error (not covered here).
- You can redirect a file as input to a command using < and << (not covered here).
Using pipe “|’
- A pipe passes standard output as the standard input to another command
Examples of the form:
- View a text file and pipe to the grep command to filter lines by looking for text.
- Cat a list and sort by line.
- Sort and then find unique items.
- View folder contents and look for a specifically named filename.

Redirection of output: > vs >>

Remember we can use grep to search a file for some text.

This output is written to the command-line

[intro_to_linux]$ grep -i bayes software.csv

Redirect this output to a file:

[intro_to_linux]$ grep -i bayes software.csv > apps.txt
[intro_to_linux]$ ls 
apps.txt  clusters  data  software.csv
[intro_to_linux]$ cat apps.txt

[intro_to_linux]$ grep -i IPA software.csv > apps.txt
[intro_to_linux]$ cat apps.txt

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Search for a File

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Intro to Linux CLI: View, Find & Search

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CLI: Intermediate Features & Summary