##### Linux "sed" Command Line Options and Examples
###### stream editor for filtering and transforming text

Sed is a stream editor. A stream editor is used to perform basic text transformations on an input stream (a file or input from a pipeline). While in some ways similar to an editor which permits scripted edits (such as ed), sed works by making only one pass over the input(s), and is consequently more efficient.

#### Usage:

sed [OPTION]... {script-only-if-no-other-script} [input-file]...

#### Command Line Options:

-n
suppress automatic printing of pattern space
 sed -n ... 
-e
add the script to the commands to be executed
 sed -e ... 
-f
add the contents of script-file to the commands to be executed
 sed -f ... 
 sed --follow-symlinks ... 
-i[SUFFIX]
edit files in place (makes backup if SUFFIX supplied)
 sed -i[SUFFIX] ... 
-l
specify the desired line-wrap length for the l' command
 sed -l ... 
--posix
disable all GNU extensions.
 sed --posix ... 
-E
use extended regular expressions in the script (for portability use POSIX -E).
 sed -E ... 
-s
consider files as separate rather than as a single, continuous long stream.
 sed -s ... 
--sandbox
operate in sandbox mode.
 sed --sandbox ... 
-u
load minimal amounts of data from the input files and flush the output buffers more often
 sed -u ... 
-z
separate lines by NUL characters
 sed -z ... 
--help
display this help and exit
 sed --help ... 
--version
output version information and exitIf no -e, --expression, -f, or --file option is given, then the first non-option argument is taken as the sedscript to interpret. All remaining arguments are names of input files; if no input files are specified, thenthe standard input is read.GNU sed home page: <http://www.gnu.org/software/sed/>. General help using GNU software:<http://www.gnu.org/gethelp/>. E-mail bug reports to: <bug-sed@gnu.org>.COMMAND SYNOPSISThis is just a brief synopsis of sed commands to serve as a reminder to those who already know sed; other doc‐umentation (such as the texinfo document) must be consulted for fuller descriptions.Zero-address commands'': labelLabel for b and t commands.#commentThe comment extends until the next newline (or the end of a -e script fragment).} The closing bracket of a { } block.Zero- or One- address commands= Print the current line number.a \text Append text, which has each embedded newline preceded by a backslash.i \text Insert text, which has each embedded newline preceded by a backslash.q [exit-code]Immediately quit the sed script without processing any more input, except that if auto-print is notdisabled the current pattern space will be printed. The exit code argument is a GNU extension.Q [exit-code]Immediately quit the sed script without processing any more input. This is a GNU extension.r filenameAppend text read from filename.R filenameAppend a line read from filename. Each invocation of the command reads a line from the file. This isa GNU extension.Commands which accept address ranges{ Begin a block of commands (end with a }).b labelBranch to label; if label is omitted, branch to end of script.c \text Replace the selected lines with text, which has each embedded newline preceded by a backslash.d Delete pattern space. Start next cycle.D If pattern space contains no newline, start a normal new cycle as if the d command was issued. Other‐wise, delete text in the pattern space up to the first newline, and restart cycle with the resultantpattern space, without reading a new line of input.h H Copy/append pattern space to hold space.g G Copy/append hold space to pattern space.l List out the current line in a visually unambiguous'' form.l widthList out the current line in a visually unambiguous'' form, breaking it at width characters. This isa GNU extension.n N Read/append the next line of input into the pattern space.p Print the current pattern space.P Print up to the first embedded newline of the current pattern space.s/regexp/replacement/Attempt to match regexp against the pattern space. If successful, replace that portion matched withreplacement. The replacement may contain the special character & to refer to that portion of the pat‐tern space which matched, and the special escapes \1 through \9 to refer to the corresponding matchingsub-expressions in the regexp.t labelIf a s/// has done a successful substitution since the last input line was read and since the last t orT command, then branch to label; if label is omitted, branch to end of script.T labelIf no s/// has done a successful substitution since the last input line was read and since the last tor T command, then branch to label; if label is omitted, branch to end of script. This is a GNU exten‐sion.w filenameWrite the current pattern space to filename.W filenameWrite the first line of the current pattern space to filename. This is a GNU extension.x Exchange the contents of the hold and pattern spaces.y/source/dest/Transliterate the characters in the pattern space which appear in source to the corresponding characterin dest.AddressesSed commands can be given with no addresses, in which case the command will be executed for all input lines;with one address, in which case the command will only be executed for input lines which match that address; orwith two addresses, in which case the command will be executed for all input lines which match the inclusiverange of lines starting from the first address and continuing to the second address. Three things to noteabout address ranges: the syntax is addr1,addr2 (i.e., the addresses are separated by a comma); the line whichaddr1 matched will always be accepted, even if addr2 selects an earlier line; and if addr2 is a regexp, itwill not be tested against the line that addr1 matched.After the address (or address-range), and before the command, a ! may be inserted, which specifies that thecommand shall only be executed if the address (or address-range) does not match.The following address types are supported:number Match only the specified line number (which increments cumulatively across files, unless the -s optionis specified on the command line).first~stepMatch every step'th line starting with line first. For example, sed -n 1~2p'' will print all theodd-numbered lines in the input stream, and the address 2~5 will match every fifth line, starting withthe second. first can be zero; in this case, sed operates as if it were equal to step. (This is anextension.)\$ Match the last line./regexp/Match lines matching the regular expression regexp.\cregexpcMatch lines matching the regular expression regexp. The c may be any character.GNU sed also supports some special 2-address forms:0,addr2Start out in "matched first address" state, until addr2 is found. This is similar to 1,addr2, exceptthat if addr2 matches the very first line of input the 0,addr2 form will be at the end of its range,whereas the 1,addr2 form will still be at the beginning of its range. This works only when addr2 is aregular expression.addr1,+NWill match addr1 and the N lines following addr1.addr1,~NWill match addr1 and the lines following addr1 until the next line whose input line number is a multi‐ple of N.REGULAR EXPRESSIONSPOSIX.2 BREs should be supported, but they aren't completely because of performance problems. The \n sequencein a regular expression matches the newline character, and similarly for \a, \t, and other sequences. The -Eoption switches to using extended regular expressions instead; the -E option has been supported for years byGNU sed, and is now included in POSIX.BUGS
 sed --version ... `