How comments are processed in shell script?

Question

I have noticed that in shell script comments are also useful to perform some task,
for ex:
if i write #!/bin/bash/
or if i write #!/bin/sh/

in both the example script behavior is different,
both are comments then why it is giving different behavior?

Answer 1

Its just a convention i.e. #! (its not #, its #!) to tell what type of the shell/interpreter it is. Your scripts can be in bash, python, perl, ruby, PHP etc by the following means

#!/bin/bash
#!/bin/sh
#!/bin/perl
#!/bin/perl5