1if [ condition ]
2then
3 # do something
4else
5 # do something else
6fi
Be very particular of the whitespace around [ and ]. It is [ condition ] and not [condition]
OR
1if [ condition ]; then
2 # do something
3else
4 # do something else
5fi
where you can place then at the end of the same line as your if condition, separated by a semi-colon ;.
For example:
1# Take user input
2read input
3
4# See if user provided twitter
5if [ "$input" == "twitter.com" ]; then
6 # show error
7 echo "can not ping this!"
8else
9 # ping three times
10 ping -c3 ${input}
11fi
ELIF is ELse IF.
1# Take user input
2read input
3
4# See if user provided twitter
5if [ $input == "twitter.com" ]; then
6 # show error
7 echo "can not ping this!"
8elif [ $input == "google.com" ]; then
9 echo "Why always Google? -_-"
10else
11 # ping three times
12 ping -c3 ${input}
13fi