리눅스 파일 내용 변경하기 - sed

리눅스 프로그램에서는 설정이 대부분 파일로 되어있다. 그래서 파일 내용 중 특정 단어나 문장르 수정해야 하는 경우가 있는데 이때 사용하는 sed 명령어에 대해 설명한다.

 

sed 명령어

주로 사용하는 명령어 형식은 아래와 같다. 

# 원본문자열을 바꿀문자열로 치환 후 파일에 저장
sed -i 's/원본문자열/바꿀문자열/g' 파일명

 

sed 명령어는 활용할 수 있는 방법이 많은데, 실제 사용했던 형식들을 이 글에 계속 업데이트할 예정이다.

 

man sed

SED(1)                                                                         User Commands                                                                        SED(1)

NAME
       sed - stream editor for filtering and transforming text

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

DESCRIPTION
       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.  But it is
       sed's ability to filter text in a pipeline which particularly distinguishes it from other types of editors.

       -n, --quiet, --silent

              suppress automatic printing of pattern space

       -e script, --expression=script

              add the script to the commands to be executed

       -f script-file, --file=script-file

              add the contents of script-file to the commands to be executed

       --follow-symlinks

              follow symlinks when processing in place

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

              edit files in place (makes backup if SUFFIX supplied)

       -l N, --line-length=N

              specify the desired line-wrap length for the `l' command

       --posix

              disable all GNU extensions.

       -E, -r, --regexp-extended

              use extended regular expressions in the script (for portability use POSIX -E).

       -s, --separate

              consider files as separate rather than as a single, continuous long stream.

       --sandbox

              operate in sandbox mode.

       -u, --unbuffered

              load minimal amounts of data from the input files and flush the output buffers more often

       -z, --null-data

              separate lines by NUL characters

       --help
              display this help and exit

       --version
              output version information and exit

       If  no  -e,  --expression,  -f, or --file option is given, then the first non-option argument is taken as the sed script to interpret.  All remaining arguments are
       names of input files; if no input files are specified, then the 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 SYNOPSIS
       This is just a brief synopsis of sed commands to serve as a reminder to those who already know sed; other documentation (such as the texinfo document) must be con‐
       sulted for fuller descriptions.

   Zero-address ``commands''
       : label
              Label for b and t commands.

       #comment
              The 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 not disabled 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 filename
              Append text read from filename.

       R filename
              Append a line read from filename.  Each invocation of the command reads a line from the file.  This is a GNU extension.

   Commands which accept address ranges
       {      Begin a block of commands (end with a }).

       b label
              Branch 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.  Otherwise, delete text in the pattern space up to the  first
              newline, and restart cycle with the resultant pattern 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 width
              List out the current line in a ``visually unambiguous'' form, breaking it at width characters.  This is a 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 with replacement.  The replacement may contain the special
              character & to refer to that portion of the pattern space which matched, and the special escapes \1 through \9 to refer to the corresponding  matching  sub-
              expressions in the regexp.

       t label
              If  a  s/// has done a successful substitution since the last input line was read and since the last t or T command, then branch to label; if label is omit‐
              ted, branch to end of script.

       T label
              If no s/// has done a successful substitution since the last input line was read and since the last t or T command, then branch to label; if label is  omit‐
              ted, branch to end of script.  This is a GNU extension.

       w filename
              Write the current pattern space to filename.

       W filename
              Write 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 character in dest.

Addresses
       Sed  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; or with two addresses, in which case the command will be executed for all input lines which match the  inclu‐
       sive  range  of  lines  starting from the first address and continuing to the second address.  Three things to note about address ranges: the syntax is addr1,addr2
       (i.e., the addresses are separated by a comma); the line which addr1 matched will always be accepted, even if addr2 selects an earlier line; and if addr2 is a reg‐
       exp, it will 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 the command 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 option is specified on the command line).

       first~step
              Match every step'th line starting with line first.  For example, ``sed -n 1~2p'' will print all the odd-numbered lines in the input stream, and the  address
              2~5  will  match every fifth line, starting with the second.  first can be zero; in this case, sed operates as if it were equal to step.  (This is an exten‐
              sion.)

       $      Match the last line.

       /regexp/
              Match lines matching the regular expression regexp.

       \cregexpc
              Match lines matching the regular expression regexp.  The c may be any character.

       GNU sed also supports some special 2-address forms:

       0,addr2
              Start out in "matched first address" state, until addr2 is found.  This is similar to 1,addr2, except that 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 a regular
              expression.

       addr1,+N
              Will match addr1 and the N lines following addr1.

       addr1,~N
              Will match addr1 and the lines following addr1 until the next line whose input line number is a multiple of N.

REGULAR EXPRESSIONS
       POSIX.2 BREs should be supported, but they aren't completely because of performance problems.  The \n sequence in a regular expression matches the newline  charac‐
       ter,  and  similarly  for  \a, \t, and other sequences.  The -E option switches to using extended regular expressions instead; the -E option has been supported for
       years by GNU sed, and is now included in POSIX.

BUGS
       E-mail bug reports to bug-sed@gnu.org.  Also, please include the output of ``sed --version'' in the body of your report if at all possible.

AUTHOR
       Written by Jay Fenlason, Tom Lord, Ken Pizzini, and Paolo Bonzini.  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>.

COPYRIGHT
       Copyright © 2017 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.

SEE ALSO
       awk(1), ed(1), grep(1), tr(1), perlre(1), sed.info, any of various books on sed, the sed FAQ (http://sed.sf.net/grabbag/tutorials/sedfaq.txt),
       http://sed.sf.net/grabbag/.

       The full documentation for sed is maintained as a Texinfo manual.  If the info and sed programs are properly installed at your site, the command

              info sed

       should give you access to the complete manual.

sed 4.4                                                                        February 2017                                                                        SED(1)