$!134 can be a nice bash foot shooter if you accidentally mistype the number

Re:$!134 can be a nice bash foot shooter if you accidentally... by boffinAudio on Tuesday December 28, 2021 @07:59AM (#29713332)

I do this too, but you know what is an even cooler and more rewarding way to exploit the shell history?

By COMMENTING your commands:

$ grep -i myname /etc/passwd # passgrep

.. ..

$ Ctrl-R "passgr"

It is so rewarding to do some intense bash work with liberal command line comments and then come back a few weeks later, "history | grep \#", and see my work notes - along with the relevant commands - available.

I used to write '~/bin' scripts for special stuff, including comments in the .sh source itself - but now it just makes more sense to wang a comment at the end of the complex/interesting commands and then just grep for the comment later ..

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Re:$!134 can be a nice bash foot shooter if you accidentally... by kevincox on Tuesday December 28, 2021 @08:23AM (#29713517)

I have a similar system but take advantage of prefix-search rather than Ctrl+r

For commands that I reuse semi-frequently I set an environment variable so that I can easily find them with prefix searching. So for example I sometimes pin IPFS paths to Infura so I have this command in my history. I can then type pin=<Up> and recall that command (until it drops off the end of my shell history).

  pin= r curl -fiXPOST "https://ipfs.infura.io:5001/api/v0/pin/add?recursive=true&arg=$(c)"

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Re:$!134 can be a nice bash foot shooter if you accidentally... by boffinAudio on Tuesday December 28, 2021 @08:30AM (#29713582)

Useful, but dangerous! I would have to check if there is already an environment variable in use before I did that ..

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Re:$!134 can be a nice bash foot shooter if you accidentally... by kevincox on Tuesday December 28, 2021 @08:32AM (#29713596)

I know this command doesn't depend on a lowercase `pin` variable so there is no danger. Note that this doesn't change the variable in the shell, just the executed command.

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Re:$!134 can be a nice bash foot shooter if you accidentally... by boffinAudio on Tuesday December 28, 2021 @08:47AM (#29713698)

Yeah, its the 'knowing beforehand' part that makes this dangerous for me. ;)

Cute trick though, will work it into my workflow and see how it feels.

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Re:$!134 can be a nice bash foot shooter if you accidentally... by kevincox on Tuesday December 28, 2021 @08:50AM (#29713735)

IDK, environment variables get set all of the time, I rarely worry about them breaking programs. Their job is kinda to live in the background and be passed through programs so it doesn't feel like much danger. Especially when I use lowercase and almost all programs use uppercase.

But I guess everyone has a different risk level and what feels near-zero to me is meaningful to someone else.

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