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제 3 장 유틸리티

숙명여대 창병모2009.09

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파일 조작 filtering, sorting, comparing, searching for

files 명령어 스케줄링

cron, at 텍스트 처리 프로그램

AWK 파일 보관 및 압축

archiving tar, gzip

유용한 유틸리티

파일 조작

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filter all lines containing a specified pattern

grep -hilnvw pattern {fileName}*fgrep -hilnvwx string {fileName}*egrep-hilnvw pattern {fileName}*

Utility Kind of patternfgrep fixed string only

grep regular expression

egrep Extended regular expression

파일 필터링

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%grep -wn the grepfile

%grep -wnv the grepfile

%grep -w x *.c

%grep -wl x *.c

%grep “.nd” grepfile

%grep “sm.*ng” grepfile

%grep “[a-m]nd” grepfile

grep: 예

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Sorting filessort -tc -r {sortField -bfMn}* {fileName}*

- sorts files in ascending or descending order

- based on sort field(s)

Comparing files

cmp -ls fileName1 fileName2 testing for the sameness

diff -i -dflag fileName1 fileName2 file differences

파일 정렬 /비교

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%sort -r sortfile

%sort +0 -1 sortfile

%sort +0 -1 -bM sortfile

%cmp lady1 lady2

%cmp -l lady1 lady2

%diff lady1 lady2

파일 정렬 /비교 : 예

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find pathList expressionrecursively descends through pathList and applies expression to every file.

expression-name pattern-user userId-atime count-print-ls-exec command

파일 찾기

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%find . -name '*.c' -print

%find . -user chang -ls

%find . -mtime 14 -ls

%find . -mtime 14 -ls -exec rm {} \;

파일 찾기 : 예

명령어 스케줄링

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What is cron system in UNIX ?- schedule a series of jobs to be executed on a periodic

basis using crontab (crontable)

crontab crontabNamecrontab -ler [userName]

1) crontab is the user interface to the cron system2) when used without any options, the crontab file calledcrontabName is registered and3) its commands are executed according to the specifiedtiming rules

주기적 실행 : cron

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Crontab file

minute hour day month

weekday command

0-59 0-23 1-31 1-12 1-7(1=Mon) UNIX command

example : a crontab file called crontab.cron

0 8 * * 1 echo Happy Monday Moring

* * * * * echo One Minute Passed >

/dev/tty1

30 14 1 * * mail users % Jan Meeting At 3 pm

주기적 실행 : cron

텍스트 처리 프로그램 :AWK

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AWK Unix 에서 처음 개발된 일반

스크립트 언어

텍스트 형태로 되어있는 데이터를 필드로 구분하여 처리하는 기능을 기본으로 한다 .

Alfred Aho, Peter Weinberger, Brian Kernighan

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awk -Fc [-f fileName] program {fileName}*Scans the lines and performs actions on every line that matches a condition

awk program is a list of commands of the form[ condition] [ { action } ]

Examplesawk ‘{ print NF, $0}’ floatawk ‘{ print $1 $3 $NF}’ floatawk ‘NR > 1 && NR <4 { print NR, $1, $3, $NF}’ float

AWK

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AWK Condition

the special token BEGIN or END an expression involving logical operators,

relational operators, and/or regular expressions

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AWK Action

if (conditional) statement [else statement] while (conditional) statement for (expression; conditional; expression)

statement break continue variable=expression

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AWK Action

print [list of expressions] printf format [, list of expressions] next

skips the remaining patterns of the current line of input)

exit skips the rest of the current line)

{list of statements}

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awk2 BEGIN { print “Start of file:”, FILENAME }

{ print $1 $3 $NF }END { print “End of file” }

awk -f awk2 float awk4

BEGIN { print “Scanning file” }{ printf “line %d: %s\n”, NR, $0; lineCount++; wordCount + = NF}

AWK: 예

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awk5 {for (I = NF; I >= 1; I--)

printf “%s “, $Iprintf “\n”}

awk6/t.*e/ {print $0}

awk7/strong/, /clear/ { print $0}

AWK: 예

파일 보관 /압축

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three utilities to archive files save files to a disk or tape tar, cpio, dump

tar maintain an archive of files on a magnetic tape create and access special tar-format archive files a file can be added on the end of tar-format file

tar -cfrtuvx [tarFileName] fileList

파일 보관

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% tar -cvf tarfile .

% tar -xvf tarfile

% tar -rvf tarfile reverse.c

% tar -cvf /dev/rst0 *

파일 보관 : 예

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compress -cv {fileName}+replaces a file by its compressed version(.Z)-c option sends the compressed version to standard output

uncompress -cv {fileName}+re-creating the original file from its compressed file

%compress -v a.c b.c%uncompress *.Z

파일 압축 : compress

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gzip {fileName}+replaces a file by its compressed version(.gz)-c option sends the compressed version to standard output

gzip -d {fileName}+decompress the original files from its compressed file

gzip -l {fileName}+list compressed file contents

%gzip -v a.c b.c%gzip –d *.gz

파일 압축 : gzip