Readjusting line breaks

How can I readjust the line breaks in my text file, for example to send it via e-mail?

The command

fmt -72 file1.txt > file2.txt

rearranges the line breaks in file1.txt such that each line ends after the first word extending it to more than 72 characters. The result is written to file2.txt.

Note that fmt works only with US ASCII text files. If your file contains, e.g., diacritical marks or typographical quotation marks, fmt will fail deliberately. Please use your standard text editor for formatting. Examples include:

Alpha

To format the paragraph the where the cursor is currently, type Cmd-I. (The command key is the one with the apple and/or cloverleaf symbols on the keyboard.) To format the entire document, type Cmd-A to select the whole text and then Cmd-I.

Emacs

Use Esc-Q to format the paragraph in which the insertion point is currently located.