Sed

Some commands

Suppose we have file input file inputfile. Here is the list of some usage of sed

Count number of lines in file (we actually print the number of the last line)

sed -n '$=' inputfile

Print everything between 'pattern1' and 'pattern2' (every pattern must be enclosed in two forward slashes)

sed -n '/pattern1/,/pattern2/p' inputfile

Delete all lines containing "text" ( d is for deletion of line)

sed '/text/d' inputfile

Delete just the word "text" (we actually substitute text with nothing)

sed 's/text//g' inputfile

Print everything from 'starthere' till the end of file. $ is a symbol to indicate last line in file and p says to print the line.

sed -n '/starthere/,$p' inputfile

Replace pattern1 with pattern2 (without option g it will replace only first instance of pattern1 in each line)

sed 's/pattern1/pattern2/g' inputfile