Shell – ZSH: What’s the difference between `.` and `source`

shellzsh

I used to think that the built-ins . and source are equivalent. This question agrees with me when it comes to bash. However I encountered the following using zsh:

desktop➜  ~/pst  . env
/usr/bin/env:1: no such file or directory:  ^@^A^@^@^@X^Z@^@^@^@^@^@@^@^@^@^@^@^@^@\M-8q^@^@^@^@^@^@^@^@^@^@@^@8^@
/usr/bin/env:2: parse error near `)'
desktop➜  ~/pst  source env
desktop➜  ~/pst  file env
env: ASCII text

source did what I expected, but what's . trying to do?

Best Answer

man zshall has the answer:

   source file [ arg ... ]
          Same as `.', except that the current directory is always searched and is always searched first, before directories in $path.

Example:

desktop➜  ~/pst  source /bin/env
/bin/env:1: no such file or directory: ^@^A^@^@^@X^Z@^@^@^@^@^@@^@^@^@^@^@^@^@\M-8q^@^@^@^@^@^@^@^@^@^@@^@8^@
/bin/env:2: parse error near `)'
desktop➜  ~/pst  . env
/usr/bin/env:1: no such file or directory: ^@^A^@^@^@X^Z@^@^@^@^@^@@^@^@^@^@^@^@^@\M-8q^@^@^@^@^@^@^@^@^@^@@^@8^@
/usr/bin/env:2: parse error near `)'

Related Solutions

How to Temporarily Bypass an Alias in tcsh

You can use a backslash:

% alias ls ls -a
% ls
# ls -a output here
% \ls
# plain ls output here

For shell builtins, there turns out to be a gotcha: a leading backslash prevents both aliases and builtins from being used, but an internal backslash suppresses aliasing only.

% alias cd pushd
% cd /tmp
/tmp /tmp 
% c\d
% dirs
~ /tmp

(I'm tempted to call that another argument against using the csh family of shells.)

In zsh, what’s the difference between &! and &|

Turns out they really are equivalent, according to man zshbuiltins (section "disown"): simply syntactic alternatives for the same operation.

Anticlimactic…

Best Answer

Related Solutions

How to Temporarily Bypass an Alias in tcsh

In zsh, what’s the difference between &! and &|

Related Question