GNU/Linux BASH builtin commands

commandline session

$pwd
/home/jeffrin/playground
$which pwd
/bin/pwd
$
$/bin/pwd
/home/jeffrin/playground
$/bin/pwd -P
/home/jeffrin/playground
$pwd -P
/home/jeffrin/playground
$help pwd
pwd: pwd [-LP]
    Print the name of the current working directory.

    Options:
      -L	print the value of $PWD if it names the current working
    	directory
      -P	print the physical directory, without any symbolic links

    By default, `pwd' behaves as if `-L' were specified.

    Exit Status:
    Returns 0 unless an invalid option is given or the current directory
    cannot be read.
$mkdir  direct
$ln -s  direct/  directlink
$pwd
/home/jeffrin/playground
$cd direct
$pwd
/home/jeffrin/playground/direct
$pwd -P
/home/jeffrin/playground/direct
$/bin/pwd
/home/jeffrin/playground/direct
$/bin/pwd -P
/home/jeffrin/playground/direct
$cd ..
$cd directlink
$pwd
/home/jeffrin/playground/directlink
$pwd -P
/home/jeffrin/playground/direct
$/bin/pwd
/home/jeffrin/playground/direct
$/bin/pwd -P
/home/jeffrin/playground/direct
$/bin/pwd --help
Usage: /bin/pwd [OPTION]...
Print the full filename of the current working directory.

  -L, --logical   use PWD from environment, even if it contains symlinks
  -P, --physical  avoid all symlinks
      --help     display this help and exit
      --version  output version information and exit

NOTE: your shell may have its own version of pwd, which usually supersedes
the version described here.  Please refer to your shell's documentation
for details about the options it supports.

Report pwd bugs to bug-coreutils@gnu.org
GNU coreutils home page: 
General help using GNU software: 
For complete documentation, run: info coreutils 'pwd invocation'
$pwd --help
bash: pwd: --: invalid option
pwd: usage: pwd [-LP]
$

GNU/Linux BASH builtin commands – Video Tutorial Related

[ source : http://www.youtube.com/user/theurbanpenguin ]