Software:fold (Unix)
| Operating system | Unix and Unix-like |
|---|---|
| Platform | Cross-platform |
| Type | Command |
| License | coreutils: GNU GPL v3 |
fold is a Unix command used for making a file with long lines more readable on a limited width computer terminal by performing a line wrap.
Most Unix terminals have a default screen width of 80, and therefore reading files with long lines could get annoying. The fold command puts a line feed every X characters if it does not reach a new line before that point. If the -w argument is set, the fold command allows the user to set the maximum length of a line.
History
fold is part of the X/Open Portability Guide since issue 4 of 1992. It was inherited into the first version of POSIX.1 and the Single Unix Specification.[1] It first appeared in 1BSD of 1977.[2][3]
The version of fold bundled in GNU coreutils was written by David MacKenzie.[4]
The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities.[5]
Example
As a usage example, to fold a file named file.txt to have a maximum of 50 characters per line, one could run the following command:
fold -w 50 file.txt
- file.txt:
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Curabitur dignissim venenatis pede. Quisque dui dui, ultricies ut, facilisis non, pulvinar non, purus. Duis quis arcu a purus volutpat iaculis. Morbi id dui in diam ornare dictum. Praesent consectetuer vehicula ipsum. Praesent tortor massa, congue et, ornare in, posuere eget, pede. Vivamus rhoncus. Quisque lacus. In hac habitasse platea dictumst. Nullam mauris tellus, sollicitudin non, semper eget, sodales non, pede. Phasellus varius ullamcorper libero. Fusce ipsum lorem, iaculis nec, vulputate vitae, suscipit vel, tortor. Cras varius. Nullam fringilla pellentesque orci. Nulla eu ante pulvinar velit rhoncus lacinia. Morbi fringilla lacus quis arcu. Vestibulum sem quam, dapibus in, fringilla ut, venenatis ut, neque.
- output:
Lorem ipsum dolor sit amet, consectetuer adipiscin g elit. Curabitur dignissim venenatis pede. Quisque dui dui, ultricies ut, fac ilisis non, pulvinar non, purus. Duis quis arcu a purus volutpat iaculis. Mo rbi id dui in diam ornare dictum. Praesent consectetuer vehicula ipsum. Prae sent tortor massa, congue et, ornare in, posuere eget, pede. Vivamus rhoncus. Quisque lacus. In hac habitasse p latea dictumst. Nullam mauris tellus, sollicitudin non, semper eget, sodales non , pede. Phasellus varius ullamcorper libero. Fusce ipsum lorem, iaculis nec , vulputate vitae, suscipit vel, tortor. Cras varius. Nullam fringilla pellentesque orci. Nulla eu ante pulvinar velit rhoncus lacinia. Morbi fringilla lacus quis arcu. Vestibul um sem quam, dapibus in, fringilla ut, venenatis ut, neque.
See also
References
- ↑ – Commands & Utilities Reference, The Single UNIX Specification, Issue 7 from The Open Group
- ↑ – FreeBSD General Commands Manual
- ↑ "fold.c – 1BSD". https://minnie.tuhs.org/cgi-bin/utree.pl?file=1BSD/s6/fold.c.
- ↑ "fold(1) - Linux man page". https://linux.die.net/man/1/fold.
- ↑ "Native Win32 ports of some GNU utilities". http://unxutils.sourceforge.net/.
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