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sponge

Introduction​

This cheat sheet provides a quick reference for some common sponge commands and concepts. sponge is a utility provided by the moreutils package on Unix-like operating systems. It is used to soak up standard input and write it to a file, making it useful for editing files in-place without intermediate files.

sponge Concepts​

Basic sponge Usage​

Sponge reads from standard input and writes to a file, allowing you to edit files in-place without using temporary files.

  • Edit a file in-place using sponge:

    command_that_generates_output | sponge filename

  • Append to a file using sponge:

    command_that_generates_output | sponge -a filename

Common Use Cases​

Sponge is often used in combination with other text-processing utilities.

  • Edit a text file in-place using sponge:

    sed 's/old-text/new-text/' filename | sponge filename

  • Remove lines containing a specific pattern from a file using sponge:

    grep -v 'pattern' filename | sponge filename

  • Sort a file in-place using sponge:

    sort filename | sponge filename

Backup Files​

To create a backup of the original file before using sponge, you can use the -b option.

  • Edit a file in-place and create a backup:
    command_that_generates_output | sponge -b filename

Multiple Input Files​

You can use sponge to merge the output of multiple commands into one file.

  • Merge the output of two commands into a single file:
    command1 | command2 | sponge outputfile

sponge Command-Line​

  • Edit a file in-place using sponge:

    command_that_generates_output | sponge filename

  • Append to a file using sponge:

    command_that_generates_output | sponge -a filename

  • Edit a text file in-place using sponge:

    sed 's/old-text/new-text/' filename | sponge filename

  • Remove lines containing a specific pattern from a file using sponge:

    grep -v 'pattern' filename | sponge filename

  • Sort a file in-place using sponge:

    sort filename | sponge filename

  • Edit a file in-place and create a backup:

    command_that_generates_output | sponge -b filename

  • Merge the output of two commands into a single file:

    command1 | command2 | sponge outputfile

Conclusion​

This cheat sheet covers some common sponge commands and concepts. sponge is a valuable tool for editing files in-place and for merging the output of multiple commands into a single file, making it useful for various text-processing tasks; refer to the sponge manual for more in-depth information and advanced usage.