| Regular Expression - Tips & Tricks | |||
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| S(tream) ED(itor) It receives text input, whether from stdin or from a file, performs certain operations on specified lines of the input, one line at a time, then outputs the result to stdout or to a file. |
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| Tip#01 To print the line numbers with space in the beginning of a file as begin start end 1 begin 2 start 3 end sed = filename | sed 'N;s/\n/ /g' |
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| Tip#02 To remove the blank lines in a file. sed -e '/^$/d' < input-file |
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| Tip#03 To change the particular pattern excpet the first occurrence in a file test pattern test test test pattern change change echo test pattern test test | sed -e '/test/change/g;s/^change/test/' |
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| Tip#04 To print only some particular lines in a file. To print the lines 1,2,3 only. sed -n 1,3p <or> sed -e 1,3!d |
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| Tip#05 To print other than the particular lines. sed -e 1,3d <or> sed -n 1,3!p |
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| Tip#06 To change a pattern to other pattern whose line is containing the particular pattern hai hello hai who are you hai hello hai this is sed Change a lines pattern hai to bye which contains a pattern as who sed -e '/who/s/hai/bye/g' < inputfile |
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| Tip#07 To change the occurrence of a particular pattern in a line. hai hello hai who are you hai hello hai this is sd To change a line's 2 second occurrence of a pattern hai to bye which contains a pattern as sed in the last of the particular line sed -e '/sd$/s/hai/bye/2' |
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| Tip#08 To show the lines which contains in the begin without the symbol "#" sed -e '/^#/d' < input_file |
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| Tip#09 To put a character ";" at end of all lines sed -e '/$/;/' < input_file |
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| Tip#10 Make the new line after the character ";" printf("Enter A");scanf(&a);printf("A=%d',a); cat input_file | sed -e 's/;/;\ <press enter> /g' It will give as printf("Enter A"); scanf(&a); printf("A=%d',a); |
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| Tip#11 To put the double space between lines. sed G filename |
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| Tip#12 To use the variables in the patterns of the sed command start hai hai sed test programme end export str=test;export str1=first sed -e 's/'$str'/'$str1'/' |
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| A (
Aho) W (
weinberger )
K ( Kernighan ) Awk is a full-featured text processing language with a syntax reminiscent of C. Awk breaks each line of input passed to it into fields. |
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| Tip#01 To find the process ID pattern - file-name or process-ID ps -ae | awk '/pattern/ { print $1 }' <or> ps -aef | grep -v awk | awk '/file-name/' { print $2}' |
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| Tip#02 To find the count of lines in a file. wc file-name | awk '{ print $1 }' |
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| Tip#03 To get the particular lines which contains the specific pattern cat file-name | awk '/pattern/ { print }' |
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| Tip#04 To print only the specific fields. Example to get the modification date time of a file. ll <Directory-Location>| awk '/file-name/ { print $6,$7,$8 }' |
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| Tip#05 To calculate the column values input_file hai 5 times bye 2 times equalto 7 times talking awk "{ total += \$2 } END { print total }" "input_file" |
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| Tip#06 To find the file size and printing with strings for the identification ls -l <file-name> | awk '{ print $9 " File size: " $5 }' |
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| Tip#07 Pattern separation with delimiter Input root:kQnW9dBGlBs6Q:0:3:exit,pwd,33333,22222:/:/usr/bin/ksh To get the passwd filed of two, cat input | awk 'BEGIN {FS=":"} { print $2 }' |
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