LinuxQuestions.org - where is command "cd" located? or is it a command/ system call?

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where is command "cd" located? or is it a command/ system call?

Neither ... it's a shell-builtin.

man bash (tcsh, ksh ... )
for details

Cheers,
Tink

It's a built-in command so it doesn't have its own file. As the previous poster mentioned, it's part of the "bash" command line program. (Bash stands for "Bourne Again Shell").

Random note: the cd shell builtin uses the chdir system call to accomplish its task. Up until about the sixth edition of Unix (sometime in the mid '70s) the change directory command in the Bourne shell was 'chdir' too. I think cd is easier to type :D.

that makes sense now, i just wrote a little shell myself, everything (well not everything technically) works but cd doesn't not work, i guess i need to write it on my own then.

By the way, cd used to be an executable on the very early Unix times (late sixties), but was broken just after the fork system call was added to the system.
Here is an excerpt from http://cm.bell-labs.com/cm/cs/who/dmr/hist.html

Quote:

Although the multiple-process idea slipped in very easily indeed, there were some aftereffects that weren't anticipated. The most memorable of these became evident soon after the new system came up and apparently worked. In the midst of our jubilation, it was discovered that the chdir (change current directory) command had stopped working. There was much reading of code and anxious introspection about how the addition of fork could have broken the chdir call. Finally the truth dawned: in the old system chdir was an ordinary command; it adjusted the current directory of the (unique) process attached to the terminal. Under the new system, the chdir command correctly changed the current directory of the process created to execute it, but this process promptly terminated and had no effect whatsoever on its parent shell! It was necessary to make chdir a special command, executed internally within the shell. It turns out that several command-like functions have the same property, for example login.

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