问题
I've read in some bash FAQ a while ago (that I don't remember), that which
should be avoided and command -v
preferred.
Why is that so? What are the advantages, disadvantages of either one?
回答1:
Well...
command
is likely built in to your shell, and with the -v
option will tell you how your shell will invoke the command specified as its option.
which
is an external binary, located at /usr/bin/which
which steps through the $PATH
environment variable and checks for the existence of a file.
A reason to select the former over the latter is that it avoids a dependency on something that is outside your shell.
The two commands do different things, and you should select the one that more closely matches your needs. For example, if command
is built in to your shell, command -v command
will indicate this with its output (through the non-existence of path), but which command
will try to point to a file on your path, regardless of how command
would be interpreted by your shell.
来源:https://stackoverflow.com/questions/37056192/which-vs-command-v-in-bash