问题
In my zsh script, I had a line
echo some text ================================
To my surprise, an error message was issued for this line:
zsh: =============================== not found
Experimenting from the command line, I found that the shell gets upset when there is an equal sign:
$ echo =z
zsh: z not found
But here, we have:
$ echo =echo
/usr/bin/echo
From this observation, it looks, as if
=XXX
would be interpreted like
$(which XXX)
However, I didn't find anything about this "substitution" in the zsh manpage. Where is this piece of magic described?
回答1:
From the docs:
14.7.3 ‘=’ expansion
If a word begins with an unquoted ‘=’ and the EQUALS option is set, the remainder of the word is taken as the name of a command. If a command exists by that name, the word is replaced by the full pathname of the command.
And here in more words
来源：https://stackoverflow.com/questions/28606988/what-special-meaning-does-an-equal-sign-have-in-zsh