The less, more, sort and sed commands are text processing commands. A word processor, or textual document preparation system, is an application used for producing (composition, editing, page layout, or formatting, possibly printing) of any type of material for printing.
The UNIX more command prints the contents of a file on the screen. The file is printed on a page-by-page basis, so it also carries the name of a pager terminal or short pager. The more command was originally implemented by Daniel Halbert, a student at the University of California at Berkeley in 1978, and was introduced in BSD 3.0. From there it has spread to all other UNIX variants, becoming a standard UNIX command.
Syntax
more [options] files
Among the most commonly used options, we mention:
–num – the number of screen lines used when the command can not detect the screen size
The UNIX less command allows you to print a text file on the screen.
The pages are printed one by one similar to the more command, unlike which less offers browsing options for forward, backward, text-level (not just page) scrolling.
Like more, less is considered a pager, it is very fast, and does not need to read the entire file from the disk to start printing. Less was written by Mark Nudelman in 1983, as a replacement for the systems that do not have navigation possibilities in the reverse direction. less is a GNU project.
Syntax
less [file options]
Among the most commonly used options, we mention:
g – highlight the found text.
I – unsolicited searches in capital letters.
M – uses a more detailed prompt that includes the position in the file.
N – print the number of lines of text; is used for code reading.
S – prints only the portion of the line of text that fits into a chop long lines.
Sed is a command used to transform text sequences. The command reads the inline files, then changes each line according to the specified rules in plain language, and displays the line.
Initially, the program was created as a UNIX utility by Lee E. McMahon at Bell Labs between 1973 and 1974 but is now available on virtually any operating system that supports a command line.
It has evolved from the grep command and is widely used with AWK for word processing from the command line or through shell programs.
The sed language has no variables, and the control structures are primitive.
Another variant of sed is minised. This is the precursor of the GNU sed. It has the advantage of being very fast and consuming little memory, making it ideal for embedded systems.
Sort is a UNIX command that sorts and prints the lines on the command line files. Sorting is based on one or more keys extracted from each data line. By default, all input data is sorted. Free space is used to divide into words. The -r option reverses the sort order.