On Thu, Mar 27, 2014 at 08:19:39AM -0700, esoj wrote: > I need to specify a variable path after #! but seems to me that bash can't > do this. > For example I need to specify the $HOME or ~ path as in: > > > #!~/bin/python > or > #!$HOME/bin/python
This belongs on help-bash, not bug-bash. That said, you can't do this directly with the shebang, because the kernel doesn't care about ~ or $HOME. It just knows file paths. (That bit in the manual about "the shell does it if the OS doesn't" is just a fallback for some really strange systems. On almost any system you are likely to use, the kernel handles the shebang, not bash. In fact, bash would only be able to handle it if you were running the program FROM bash in the first place.) The typical workaround is to write some clever boilerplate code at the top of the script which is interpreted a comment (or a no-op) in one language, and a valid instruction (to reinvoke the program with a different interpreter) in another language. In this case, you want the shebang to be #!/bin/sh, and you want boilerplate code that invokes the script under ~/bin/python when the script is run by /bin/sh, but which does nothing when it's invoked by python. I would imagine some Python FAQ has this somewhere... let's see what Google turns up. http://softwareswirl.blogspot.com/2011/06/starting-python-script-intelligently.html http://stackoverflow.com/questions/19304295/make-usr-bin-env-python-u-shebang-portable There, that's not bad. The first answer in the second URL is nice and short.
