Re: [Libguestfs] shebang usage in bash scripts

> > Shebang interpretation is sometimes by the kernel, and sometimes by > the shell, and it differs by OS. Some OS's do word-splitting on the > rest of the shebang after the first space, some treat the entire rest > of the line as a single argument. > > For a nice summary of some of the warts of shebang lines, see > > https://unix.stackexchange.com/questions/29608/why-is-it-better-to-use-us... > > If you are worried about /bin/bash being available on all systems > where a v2v script will be installed, you probably want '#!/bin/env > bash' to find the first bash in PATH. But once you add your first > whitespace, it is no longer portable to use any others, so while > '#!/bin/bash -' works, '#!/bin/env bash -' does not. I find that the > issue of writing a shebang to use a program that may not always be > installed in the same absolute location across all OSs (and therefore > where '#!/bin/env name' is useful) is more common than the issue of > writing a shebang that wants to pass an explicit '-' or '--' > end-of-option marker to protect against the script being installed > under a name like '-c ls'. Fedora packaging guidelines -- rightly or wrongly -- forbid #!/usr/bin/env: https://docs.fedoraproject.org/en-US/packaging-guidelines/#_shebang_lines although apparently RPM rewrites them automatically so perhaps we would not notice.