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62 lines
1.5 KiB
Markdown
62 lines
1.5 KiB
Markdown
# Where And Which Are Whence
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I was recently watch some of the commands being run by an AI agent in a coding
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harness. One in particular caught my attention because it wasn't one I was
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familiar with. It was the command `whence`.
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The `man zshbuiltins` describe `whence` like so:
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> For each name, indicate how it would be interpreted if used as a command name.
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I'd describe it myself as a utility for surfacing what a given command name
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corresponds to when it gets executed. For instance, when run against the name
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`cat` in my local setup, I see `bat` which is explained by the alias I set up.
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```bash
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❯ whence cat
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bat
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```
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There are several flags that can be used with `whence`. The underlying behavior
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for `whence` is what is also used for more familiar commands like `where` and
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`which`.
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```
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where [ -wpmsS ] [ -x num ] name ...
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Equivalent to whence -ca.
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which [ -wpamsS ] [ -x num ] name ...
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Equivalent to whence -c.
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```
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I can get a clearer answer that `cat` is an alias with `-c`.
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```bash
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❯ whence -c cat
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cat: aliased to bat
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```
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And with `-ca`, I can see that `cat` resolves several different times on the
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path with the alias to `bat` taking precedence over all of that.
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```bash
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❯ whence -ca cat
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cat: aliased to bat
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/bin/cat
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/bin/cat
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/bin/cat
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/bin/cat
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/bin/cat
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/bin/cat
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```
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The other command that uses the underlying `whence` functionality is `type`.
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```
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type [ -wfpamsS ] name ...
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Equivalent to whence -v.
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```
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See `man zshbuiltins` for more details. There are more flags which can be used
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to get additional info.
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