data_lab

1 2 3 4 5 # Read from the file file.txt and output all valid phone numbers to stdout. #!/bin/sh sed -n -r '/^([0-9]{3}-|\([0-9]{3}\) )[0-9]{3}-[0-9]{4}$/p' file.txt Colored by Color Scripter cs

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 # Read from the file file.txt and output the tenth line to stdout. #!/bin/sh line_number=$(wc -l ./file.txt | awk '{print $1}') #echo $(expr ${line_number}) cat ./file.txt | while read line do if [ ${line_number} -eq 10 ] then echo $(cat file.txt | sed -n 10p) break else echo $(cat file.txt | sed -n 10p) break fi done Colored by Color Scripter cs