Just don't call it with #!/bin/sh. Because that's POSIX shell, not bash.
but effectively it's bash, I think /bin/sh is a symlink to bash on every system I know of...
Edit: I feel corrected, thanks for the information, all the systems I used, had a symlink to bash. Also it was not intended to recommend using bash functionality when having a shebang !#/bin/sh. As someone other pointed out, recommendation would be #!/usr/bin/env bash, or !#/bin/sh if you know that you're not using bash specific functionality.
Still don't do this. If you use bash specific syntax with this head, that's a bashism and causes issues with people using zsh for example. Or with Debian/*buntu, who use dash as init shell.
Just use #!/bin/bash or #!/usr/bin/env bash if you're funny.
#!/bin/bash doesn't work on NixOS since bash is in the nix store somewhere, #!/usr/bin/env bash resolves the correct location regardless of where bash is
Are there any distos with /usr/bin/env in a different spot? I still believe that's the best approach for getting bash.
All posix-compliant distros need /usr/bin/env
I do think a simple symlink is superior to a tool parsing stuff. A shame POSIX choose this approach.
Still the issue that a posix shell can be on a non-posix system and vice versa. And certificates versus used practice. Btw, isn't there only one posix certified Linux distro? Was it Suse?
Posix certification is dumb but posix compliance is nice to ensure some level of compatibility.
Symlinks would be pretty bad in the case of nixos. Wouldn't fit at all
/bin/bash won't work on every system
for example NixOS
some other systems may have bash in /usr/bin or elsewhere
NixOS didn't do /usr merge?
Binaries are not in /usr/bin or /bin except for /bin/sh and /usr/bin/env. Programs should not assume fixed paths for binaries and instead look for them in $PATH.
Beginning with DebianSqueeze, Debian uses Dash as the target of the /bin/sh symlink. Dash lacks many of the features one would expect in an interactive shell, making it faster and more memory efficient than Bash.
From DebianSqueeze to DebianBullseye, it was possible to select bash as the target of the /bin/sh symlink (by running dpkg-reconfigure dash). As of DebianBookworm, this is no longer supported.
It is a symlink, but bash will automatically enable posix compliance mode if you use it. So any bash specific features will bomb out unless you explicitly reset it in the script.
Wut that is not even the case for Ubuntu. You're probably thinking of dash example:
sh -c '[[ true ]] && echo ya'
# sh: 1: [[: not found
bash -c '[[ true ]] && echo ya'
# ya
i thought most unix-like systems had it symlinked to a shell like dash. it's what i have on my system (void linux), of course not as an interactive shell lol
i use #!/bin/sh for posix scripts and #!/usr/bin/env bash for bash scripts. #!/bin/sh works for posix scripts since even if it's symlinked to bash, bash still supports posix features.
Just don't call it with
#!/bin/sh. Because that's POSIX shell, not bash.but effectively it's bash, I think
/bin/shis a symlink to bash on every system I know of...Edit: I feel corrected, thanks for the information, all the systems I used, had a symlink to bash. Also it was not intended to recommend using bash functionality when having a shebang
!#/bin/sh. As someone other pointed out, recommendation would be#!/usr/bin/env bash, or!#/bin/shif you know that you're not using bash specific functionality.Still don't do this. If you use bash specific syntax with this head, that's a bashism and causes issues with people using zsh for example. Or with Debian/*buntu, who use dash as init shell.
Just use
#!/bin/bashor#!/usr/bin/env bashif you're funny.#!/bin/bashdoesn't work on NixOS since bash is in the nix store somewhere,#!/usr/bin/env bashresolves the correct location regardless of where bash isAre there any distos with
/usr/bin/envin a different spot? I still believe that's the best approach for getting bash.All posix-compliant distros need /usr/bin/env
I do think a simple symlink is superior to a tool parsing stuff. A shame POSIX choose this approach.
Still the issue that a posix shell can be on a non-posix system and vice versa. And certificates versus used practice. Btw, isn't there only one posix certified Linux distro? Was it Suse?
Posix certification is dumb but posix compliance is nice to ensure some level of compatibility.
Symlinks would be pretty bad in the case of nixos. Wouldn't fit at all
My own. I use arch btw
/bin/bashwon't work on every system for example NixOS some other systems may have bash in /usr/bin or elsewhereNixOS didn't do /usr merge?
Binaries are not in
/usr/binor/binexcept for/bin/shand/usr/bin/env. Programs should not assume fixed paths for binaries and instead look for them in$PATH.No no no no no, do not believe this you will shoot yourself in the foot.
https://wiki.debian.org/Shell
It is a symlink, but bash will automatically enable posix compliance mode if you use it. So any bash specific features will bomb out unless you explicitly reset it in the script.
Wut that is not even the case for Ubuntu. You're probably thinking of
dashexample:i thought most unix-like systems had it symlinked to a shell like
dash. it's what i have on my system (void linux), of course not as an interactive shell loli use
#!/bin/shfor posix scripts and#!/usr/bin/env bashfor bash scripts.#!/bin/shworks for posix scripts since even if it's symlinked to bash, bash still supports posix features.macOS
Debian
Ubuntu