To reverse a file using awk and print next three lines after pattern match (Including pattern):
awk '{ a[i++] = $0 } END { for (j=i-1; j>=0;) print a[j--] }' abcd.txt |sed -n '/MANU/{p;n;p;n;p;n;p;}' >abcd_new.txt
(This can be used when you want to print 3 lines before pattern match, including pattern. Logic: reverse a file and print 3 lines after pattern match.)
How to reverse a file using awk:
awk '{ a[i++] = $0 } END { for (j=i-1; j>=0;) print a[j--] }' abcd.txt
How to reverse a file using sed:
sed -n '1!G;h;$p' abcd.txt
how to get yesterday date in unix
YEST=`TZ="GMT+24" date +'%m/%d/%Y'`; echo $YEST
Replace Text : sed -e "s/Old/New/g"
Remove Text : sed -e "s/Text//g"
Remove Text From Front : sed -e "s/^Text//g"
Remove Text From End :
sed -e "s/Text\$//g"
sed -e 's/Text$//g'
Insert Text in Front : sed -e "s/^/Text/g"
Append Text to End :
sed -e "s/\$/Text/g"
sed -e 's/$/Text/g'
Truncate :
sed -e "s/Text.*//"
cut -c5-8
Downshift and Upshift :
tr '[A-Z]' '[a-z]'
tr '[a-z]' '[A-Z]'
Change Tabs to Spaces : sed -e "s/<tab>/ /g"
Change Multiple Spaces to a Single Space :
sed -e "s/ */ /g"
Change Whitespaces to a Single Space :
sed -e "s/[<tab><space>][<tab><space>]*/<space>/g"
Delete Leading Whitespaces:
sed -e "s/^[<tab><space>]*//g"
Delete Trailing Whitespaces:
sed -e 's/[<tab><space>]*$//g'
Delete Lines:
sed -e "/Text/d"
grep -v "Text"
Delete Empty Lines:
sed -e '/^*$/d'
sed -e '/^[<tab><space>]*$/d'
Delete First Line:
sed -e '1d'
sed -e '1,7d'
Delete Last Line : sed -e '$d'
Print First Line :
sed -n '1p'
sed -e '2,$d'
sed -e '1q'
Print Last Line :
sed -n '$p'
Delete Comments :
sed -e '/^#/d'
sed -e 's/#.*//'
Delete Text Between Keywords :
sed -e '/Keyword1/,/Keyword2/d'
sed -e '/^Keyword1$/,/^Keyword2$/d'
Extract Text Between Keywords :
sed -e '/^Keyword1$/,/^Keyword2$/!d'
Print Odd Lines : cat -n file | sed -e '/.....[02468]/d' -e 's/^.......//'
Print Even Lines : cat -n file | sed -e '/.....[13579]/d' -e 's/^.......//'
Read a File Backwards : cat -n file | sort -nr | sed 's/^.......//'
Convert < > into LTGT : cat $* | sed -e 's/</\</g' -e 's/>/\>/g'
