Question

In a bash script is there an “official” way to run different commands based on, for example, OS version. I mean in a way that you can basically set it once at the top and then call it the same way everywhere else.
I’ve tried to use aliases but that seems to be a crapshoot and doesn’t really work on some systems (one is Windows 7 using win-bash).

For example, this is what I tried:

if [ "$(uname)" = "Darwin" ]; then
    alias p4cli=./bin/p4
else
    alias p4cli=C:\bin\p4.exe
fi

p4cli login

It works on Mac if I use shopt -s expand_aliases but win-bash doesn’t have shopt.
I’m assuming there’s a better way than aliases to do this?

Answer 1

To determine underlying OS in bash it is better to depend on env variable OSTYPE. The bash manpage says that the variable OSTYPE stores the name of the operation system:

OSTYPE Automatically set to a string that describes the operating
system on which bash is executing. The default is system- dependent.

if [[ "$OSTYPE" == "darwin"* ]]; then
   p4cli="./bin/p4"
else
   p4cli="C:\bin\p4.exe"
fi

"$p4cli" login