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Operating system | Unix and Unix-like |
---|---|
Platform | Cross-platform |
Type | Command |
expand
is a program that converts tab characters into groups of space characters, while maintaining correct alignment. It is available in Unix operating systems and many Unix-like operating systems. [1] 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. [2]
For example:
$ echo -e "foo\tbar"| expand | xxd -g 1 -u 0000000: 66 6F 6F 20 20 20 20 20 62 61 72 0A foo bar.$ echo -e "foo\tbar"| xxd -g 1 -u 0000000: 66 6F 6F 09 62 61 72 0A foo.bar.$
Here the echo
command prints a string of text that includes a tab character, then the output is directed into the expand
command. The resulting output is then displayed in hexadecimal and as characters by the xxd
dump command. At the second prompt, the same echo
output is sent directly to the xxd
command. As can be seen by comparing the two, the expand
program converts the tab (specified as '\t' to the echo
program) into spaces.
uniq
is a utility command on Unix, Plan 9, Inferno, and Unix-like operating systems which, when fed a text file or standard input, outputs the text with adjacent identical lines collapsed to one, unique line of text.
In software development, Make is a build automation tool that builds executable programs and libraries from source code by reading files called Makefiles which specify how to derive the target program. Though integrated development environments and language-specific compiler features can also be used to manage a build process, Make remains widely used, especially in Unix and Unix-like operating systems.
The comm command in the Unix family of computer operating systems is a utility that is used to compare two files for common and distinct lines. comm is specified in the POSIX standard. It has been widely available on Unix-like operating systems since the mid to late 1980s.
xargs is a command on Unix and most Unix-like operating systems used to build and execute commands from standard input. It converts input from standard input into arguments to a command.
join
is a command in Unix and Unix-like operating systems that merges the lines of two sorted text files based on the presence of a common field. It is similar to the join operator used in relational databases but operating on text files.
bc, for basic calculator, is "an arbitrary-precision calculator language" with syntax similar to the C programming language. bc is typically used as either a mathematical scripting language or as an interactive mathematical shell.
wc
is a command in Unix, Plan 9, Inferno, and Unix-like operating systems. The program reads either standard input or a list of computer files and generates one or more of the following statistics: newline count, word count, and byte count. If a list of files is provided, both individual file and total statistics follow.
In computing, echo
is a command that outputs the strings that are passed to it as arguments. It is a command available in various operating system shells and typically used in shell scripts and batch files to output status text to the screen or a computer file, or as a source part of a pipeline.
In Unix and Unix-like operating systems, iconv is a command-line program and a standardized application programming interface (API) used to convert between different character encodings. "It can convert from any of these encodings to any other, through Unicode conversion."
In computing, cut
is a command line utility on Unix and Unix-like operating systems which is used to extract sections from each line of input — usually from a file. It is currently part of the GNU coreutils package and the BSD Base System.
nl is a Unix utility for numbering lines, either from a file or from standard input, reproducing output on standard output.
unexpand is a command in Unix and Unix-like operating systems. It is used to convert groups of space characters into tab characters.
rm
is a basic command on Unix and Unix-like operating systems used to remove objects such as computer files, directories and symbolic links from file systems and also special files such as device nodes, pipes and sockets, similar to the del
command in MS-DOS, OS/2, and Microsoft Windows. The command is also available in the EFI shell.
In computing, sleep is a command in Unix, Unix-like and other operating systems that suspends program execution for a specified time.
expr is a command line utility on Unix and Unix-like operating systems which evaluates an expression and outputs the corresponding value. It first appeared in Unix v7. The command is available for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. The expr command has also been ported to the IBM i operating system.
dirname
is a standard computer program on Unix and Unix-like operating systems. When dirname
is given a pathname, it will delete any suffix beginning with the last slash ('/'
) character and return the result. dirname
is described in the Single UNIX Specification and is primarily used in shell scripts.
od
is a command on various operating systems for displaying ("dumping") data in various human-readable output formats. The name is an acronym for "octal dump" since it defaults to printing in the octal data format.
The csplit
command in Unix and Unix-like operating systems is a utility that is used to split a file into two or more smaller files determined by context lines.
GNU parallel is a command-line driven utility for Linux and other Unix-like operating systems which allows the user to execute shell scripts or commands in parallel. GNU parallel is free software, written by Ole Tange in Perl. It is available under the terms of GPLv3.
cat
is a standard Unix utility that reads files sequentially, writing them to standard output. The name is derived from its function to (con)catenate files. It has been ported to a number of operating systems.