I just installed sdkman for installing grails on my machine (MacOS). When I run which sdk command I don't get any output. But when I run the sdk help command the shell is able to resolve it and give the the right output. I checked all the directories mentioned in $PATH environment variable but I could not find any executable sdk. So my question is how is shell able to resolve the sdk command?
Note: I also checked in Ubuntu and I see the same behavior.
OK. So I found it out. As @that-other-guy mentioned in the comment above, I used type -a instead of which, which showed me that it was a function defined.
As you mentioned correctly "sdk" is not a command, its a declared function created by sdkman-main.sh (in ~/.sdkman/src) once called from ~/.sdkman/bin/sdkman-init.sh
This is the reason why the installation page of sdkman asks for appending the following steps in the .bash_profile which declares this function each time the bash profile is loaded :
#THIS MUST BE AT THE END OF THE FILE FOR SDKMAN TO WORK!!!
[[ -s "/home/dudette/.sdkman/bin/sdkman-init.sh" ]] && source "/home/dudette/.sdkman/bin/sdkman-init.sh"
This is also the reason "which" command doesn't pick it up as it checks for the installed commands on the linux PATH
来源：https://stackoverflow.com/questions/44988259/where-is-the-sdk-command-installed-for-sdkman