Pwd

In Unix-like and some other operating systems, the codice_1 command ("print working directory") writes the full pathname of the current working directory to the standard output.
Implementations.
Multics had a codice_1 command (which was a short name of the codice_3 command) from which the Unix pwd command originated. The command is a shell builtin in most Unix shells such as Bourne shell, ash, bash, ksh, and zsh. It can be implemented easily with the POSIX C functions codice_4 or codice_5.
It is also available in the operating systems SpartaDOS X, PANOS, and KolibriOS. The equivalent on DOS (codice_6) and Microsoft Windows (codice_7) is the codice_8 command with no arguments. Windows PowerShell provides the equivalent codice_9 cmdlet with the standard aliases codice_10 and codice_1.
On Windows CE 5.0, the codice_7 "Command Processor Shell" includes the codice_1 command. 
 as found on Unix systems is part of the X/Open Portability Guide since issue 2 of 1987. It was inherited into the first version of POSIX.1 and the Single Unix Specification. It appeared in Version 5 Unix. The version of codice_1 bundled in GNU coreutils was written by Jim Meyering.
The numerical computing environments MATLAB and GNU Octave include a codice_1 
function with similar functionality. The OpenVMS equivalent is codice_16.
*nix examples.
Note: POSIX requires that the default behavior be as if the -L switch were provided.
Working directory shell variables.
POSIX shells set the following environment variables while using the cd command: