bash - Replacing string in linux using sed/awk based -

i want replace this

#!/usr/bin/env bash

with this

   #!/bin/bash

i have tried 2 approaches

approach 1

original_str="#!/usr/bin/env bash" replace_str="#!/bin/bash"  sed s~${original_str}~${replace_str}~ filename

approach 2

line=`grep -n "/usr/bin" filename` awk nr==${line} {sub("#!/usr/bin/env bash"," #!/bin/bash")}

but both of them not working.

you cannot use ! inside double quotes in bash otherwise history expansion take place.

you can do:

original_str='/usr/bin/env bash' replace_str='/bin/bash'  sed "s~$original_str~$replace_str~" file #!/bin/bash

Ruby Co