O'Reilly logo

Linux in a Nutshell, 6th Edition by Robert Love, Stephen Figgins, Ellen Siever, Arnold Robbins

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Output Redirections

For print and printf, dest-expr is an optional expression that directs the output to a file or pipe.

> file

Direct the output to a file, overwriting its previous contents.

>> file

Append the output to a file, preserving its previous contents. In both this case and the > file case, the file will be created if it does not already exist.

| command

Direct the output as the input to a system command.

|& command

Direct the output as the input to a coprocess. gawk only.

Be careful not to mix > and >> for the same file. Once a file has been opened with >, subsequent output statements continue to append to the file until it is closed.

Remember to call close( ) when you have finished with a file, pipe, or coprocess. If you don’t, eventually you will hit the system limit on the number of simultaneously open files.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required