10.2. Command-Line Syntax

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The syntax for invoking sed has two forms:

     sed [-n] [-e] 'command' file(s)     sed [-n]  -f  scriptfile file(s)

The first form allows you to specify an editing command on the command line, surrounded by single quotes. The second form allows you to specify a scriptfile, a file containing sed commands. Both forms may be used together, and they may be used multiple times. If no file (s) is specified, sed reads from standard input.

10.2.1. Standard Options

The following options are recognized:


-n

Suppress the default output; sed displays only those lines specified with the p command or with the p flag of the s command.


-e cmd

Next argument is an editing command. Necessary if multiple scripts or commands are specified.


-f file

Next argument is a file containing editing commands.

If the first line of the script is #n, sed behaves as if -n had been specified.

Multiple -e and -f options may be provided, and they may be mixed. The final script consists of the concatenation of all the script and file arguments.

10.2.2. GNU sed Options

GNU sed accepts a number of additional command-line options, as well as long-option equivalents for the standard options. The GNU sed options are:


-e cmd, --expression cmd

Use cmd as editing commands.


-f file, --file file

Obtain editing commands from file.


--help

Print a usage message and exit.


-i[suffix], --in-place[= suffix]

Edit files in place, overwriting the original file. If optional suffix is supplied, use it for renaming the original file as a backup file. See the GNU sed online Info documentation for the details.


-l len, --line-length len

Set the line length for the l command to len characters.


-n, --quiet, --silent

Suppress the default output; sed displays only those lines specified with the p command or with the p flag of the s command.


--posix

Disable all GNU extensions. Setting POSIXLY_CORRECT in the environment merely disables those extensions that are incompatible with the POSIX standard.


-r, --regex-extended

Use Extended Regular Expressions instead of Basic Regular Expressions. See Chapter 7 for more information.


-s, --separate

Instead of considering the input to be one long stream consisting of the concatenation of all the input files, treat each file separately. Line numbers start over with each file; the address $ refers to the last line of each file; files read by the R command are rewound; and range addresses (/x/,/y/) may not cross file boundaries.


-u, --unbuffered

Buffer input and output as little as possible. Useful for editing the output of tail -f when you don't want to wait for the output.


--version

Print the version of GNU sed and a copyright notice, and then exit.

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    Unix in a Nutshell
    Unix in a Nutshell, Fourth Edition
    ISBN: 0596100299
    EAN: 2147483647
    Year: 2005
    Pages: 201

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