find . -name 'soccer_scores.csv' -exec cat {} + | grep 1959
get word counts of either Sydney Carton or Charles Darnay from two_cities.txt
cat two_cities.txt | grep -E 'Sydney Carton|Charles Darnay' | wc -l
cat animals.txt | cut -d “ “ -f 2 | sort | uniq -c
change "Cherno” to “Cherno City”
cat soccer_scores.csv | sed 's/Cherno/Cherno City/g' > soccer_scores_edited.csv
$@ : "all of the command-line parameters given to the script".
$ cat [count-records.sh](<http://count-records.sh/>) # tail -q -n +2 $@ | wc -l
$ sh count-records.sh seasonal/*.csv # tail -q -n +2 $seasonal/*.csv | wc -l
$1 $2: first, second parameter
$# : number of arguments
# backticks
a="Date : `Date`"
echo $a # Date : 2022년 9월 4일 일요일 17시 12분 11초 KST
# parentheses
b="Date : $(Date)"
echo $b # Date : 2022년 9월 4일 일요일 17시 12분 21초 KST