pbcopy和pbpaste
echo "123" | pbcopy
echo `pbpaste`
expr
expr 1 + 1
expr 1 {/,%,*,-,=, >, >=, <, <=, !=} 1
expr "//asdfc" : '.*/\(.*\)'
cal
cal
echo "123" | pbcopy
echo `pbpaste`
expr 1 + 1
expr 1 {/,%,*,-,=, >, >=, <, <=, !=} 1
expr "//asdfc" : '.*/\(.*\)'
cal