Linux fold Command
The Linux fold command is used to limit the column width of files.
The fold command reads content from the specified file, adds line-breaking characters to columns that exceed the specified column width, and outputs the result to the standard output device. If no file name is specified, or if the provided file name is "-", the fold command reads data from the standard input device.
Syntax
fold [-bs][-w<width>][--help][--version][file...]
Parameters:
- -b or --bytes: Calculate column width in bytes instead of line numbers.
- -s or --spaces: Use space characters as line break points.
- -w<width> or --width<width>: Set the maximum number of lines per column.
- --help: Display online help.
- --version: Show version information.
Example
To fold the lines of a file named testfile to a width of 30, you can use the following command:
fold -w 30 testfile
For comparison, first output the contents of testfile:
$ cat testfile # View the contents of testfile
Linux networks are becoming more and more common, but
security is often an overlooked
issue. Unfortunately, in today’s environment all networks
are potential hacker targets,
from top-secret military research networks to small home LANs.
Linux Network Security focuses on securing Linux in a
networked environment, where the
security of the entire network needs to be considered
rather than just isolated machines.
It uses a mix of theory and practical techniques to
teach administrators how to install and
use security applications, as well as how the
applications work and why they are necessary.
Then use the fold command to display the folded lines:
$ fold -w 30 testfile # Fold lines to a width of 30 and display the testfile
Linux networks are becoming mo
re and more common, but securi
ty is often an overlooked issu
e. Unfortunately, in today’s
environment all networks are
potential hacker targets, from
top-secret military research
networks to small home LANs.
Linux Network Security focuses
on securing Linux in a networ
ked environment, where the sec
urity of the entire network ne
eds to be considered rather th
an just isolated machines. It
uses a mix of theory and pract
ical techniques to teach admin
istrators how to install and u
se security applications, as w
ell as how the applications wo
rk and why they are necessary