sed 's/old/new/g' fileReplace all occurrences
sed 's/old/new/' fileReplace first occurrence
sed -i 's/old/new/g' fileReplace in-place
sed '/pattern/d' fileDelete matching lines
sed '5d' fileDelete 5th line
sed '1,5d' fileDelete lines 1-5
sed '/pattern/p' filePrint matching lines
sed -n '/pattern/p' fileOnly print matching lines
sed '5!p' filePrint all except 5th line
sed -n '5,10p' filePrint lines 5-10
sed 's/^# //' fileUncomment lines
sed '/^$/d' fileDelete empty lines
sed '1i header' fileInsert at line 1
sed '$a footer' fileAppend at last line
sed 'y/abc/xyz/' fileTranslate characters
sed '3q' fileQuit after line 3
sed '/pattern/,/end/d' fileDelete range
sed -e 'cmd1' -e 'cmd2' fileMultiple commands
sed -f script.sed fileRun script file
sed 's/\t/ /g' fileReplace tabs with spaces
sed 's/ *$//' fileTrim trailing spaces
sed '/pattern/!d' fileKeep only matching lines
sed '=' filePrint line numbers
sed -n '10p' filePrint 10th line
sed '/^$/d; /^#/d' fileDelete empty and comment lines