I know that pwd gives the current working directory, hostname gives the current host and whoami gives the current user. Is there a single unix command that will give me the output of ...
how does built in commands of a shell implemented in Linux? as a function or thread of shell process?
I know that external commands are run in the shell by creating a separate process. But what exactly happens when a built in command is run in a shell. Are they executed as a function or if the shell ...
According to the Open Group, [t]he return utility shall cause the shell to stop executing the current function or dot script. If the shell is not currently executing a function or dot script, ...
Under some answers, I see comments that recommend avoiding shell specific commands in answers. How do I know which commands, operators, etc exist in all shells? Is there a list of standards? man ...
Is there any intrinsic difference between a builtin command and another command which can nominally do the same thing? eg. Do builtins get "special" treatement? ... is there less overhead running ...
$ which echo echo: shell built-in command. $ which ls /bin/ls $ which cat /bin/cat Why is echo not an independent utility like ls, ps, cat etc? Why is it shell specific? Any good reasons?