6
¥Command Types
_consider the commands:
/bin/ls ~
ls ~
cd ~
wc
~/AFNI_data1/afni/ideal_r1.1D
_the "which" command shows
where the shell gets a command from:
which ls
which cdwhich
wc
which cdwhich
wc_the shell must decide what type of
command it has:
"full pathname for a program: execute that
program
"alias: apply any alias(es) then start over
(decide on which program to run)
"shell command: part of the /bin/tcsh program
"check the $PATH
directories for the program
¥The PATH Variable
_a list of directories to be
searched for a given program to be run from
_the $path
and $PATH variables are
identical, but are represented differently
_commands:echo $PATH
echo $PATHecho $pathcat ~/.cshrc