파일 조작 파일 조작 filtering, sorting, comparing, searching for files 명령어 스케줄링

파일 조작

• 파일 조작

• filtering, sorting, comparing, searching for files

• 명령어 스케줄링

• cron, at

• 텍스트 처리 프로그램

• AWK

• 파일 보관 및 압축

• archiving
• tar, gzip

• filter all lines containing a specified pattern

• %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

Sorting files

• Sorting files

• sort -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

• %sort -r sortfile
• %sort +0 -1 sortfile
• %sort +0 -1 -bM sortfile
• %cmp lady1 lady2
• %cmp -l lady1 lady2
• %diff lady1 lady2

find pathList expression

• find pathList expression

• recursively descends through pathList and applies expression to every file.

• expression

• -name pattern

• -user userId

• -atime count

• -print

• -ls

• -exec command

• %find . -name '*.c' -print

• %find . -user chang -ls

• %find . -mtime 14 -ls

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

Unix에서 처음 개발된 일반 스크립트 언어

• Unix에서 처음 개발된 일반 스크립트 언어

• 텍스트 형태로 되어있는 데이터를 필드로 구분하여 처리하는 기능을 기본으로 한다.

• Alfred Aho, Peter Weinberger, Brian Kernighan

• 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 } ]

• Examples

• awk ‘{ print NF, $0}’ float

• awk ‘{ print $1 $3 $NF}’ float

• awk ‘NR > 1 && NR <4 { print NR, $1, $3, $NF}’ float

Condition

• Condition

• the special token BEGIN or END
• an expression involving logical operators, relational operators, and/or regular expressions

Action

• Action

• if (conditional) statement [else statement]
• while (conditional) statement
• for (expression; conditional; expression) statement
• break
• continue
• variable=expression

Action

• 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}

awk2

• 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

• }

awk5

• awk5

• {for (I = NF; I >= 1; I--)

• printf “%s “, $I

• printf “\n”

• }

• awk6

• /t.*e/ {print $0}

• awk7

• /strong/, /clear/ { print $0}

three utilities to archive files

• 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

% tar -cvf tarfile .

• % tar -cvf tarfile .
• % tar -xvf tarfile
• % tar -rvf tarfile reverse.c
• % tar -cvf /dev/rst0 *

compress -cv {fileName}+

• 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

gzip {fileName}+

• 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