Using hashtags to organize your bash history (opens in new tab)

(vignesh.foamsnet.com)

53 pointsvigneshv_psg12y ago19 comments

19 comments

15 comments · 7 top-level

mooism212y ago· 7 in thread

Or you could stick the command in a shell script.

  #!/bin/sh
  find . -iname '*.php' -print0 | xargs -0 -n1 php -l

Save it to ~/bin/phplint (you do have ~/bin in your PATH, right?), chmod +x it, check it in, and you have a new phplint command. No need to mess about with hashtags in your shell history.

Am I missing something?

twic12y ago

What you may be missing is the difference in length between:

  Create a file ~/bin/phplint
  Type out the shebang
  Copy the command from the terminal into the file
  Save the file
  chmod +x the file

And:

  type #phplint

I'm sure Mr Venkat wouldn't claim that he has rendered script directories overnight. But he has come up with a way to make your shell history a little more usable.

I observe that people vary a lot in how hard they lean on their history. I live and die by mine; it serves as a combination of replacement short-term memory and treasury of tricks. Some of my colleagues don't really use it at all, using scripts or aliases, or even just retyping commands every time, like savages. If you're not a heavy user of history, then this idea won't help you. If you are, it might.

mooism212y ago

You're right, the first alternative is disgustingly long-winded. Let's automate it.

Create a new shell script called `empty` somewhere on your PATH:

  #!/bin/bash
  set -e
  exec >"$1"
  printf '#!'
  which "$2"
  chmod +x "$1"
  cat

Next, add a new shell function to your ~/.bashrc:

  save-history() {
    history -p "$1" | empty ~/bin/"$2" bash
  }

To save the most recent command in your history to a shell script called ~/bin/phplint, run

  save-history '!!' phplint

You have to single-quote the '!!'; sorry about that. I'm using bash; maybe zsh has some way of making this easier to use.

Having said that, if you're happy (I'm speaking generically here, not specifically to twic) relying on your history, then more power to you. It doesn't work for me because I haven't worked out yet how to keep my shell history straight between several shell sessions on the same PC, let alone syncing it between different PCs.

1 more reply

ibotty12y ago

no you are not. but some one-offs are good enough to reuse, but not good enough to open an editor for, depend on environment variables (which might be spelled out in the command), or something. so although i do use a pretty well populated ~/bin (well ~/usr/bin) and many shell functions, i will adopt that practice. it might even work out for script files (i.e. recordings of your shell session).

drdaeman12y ago

> not good enough to open an editor for

It's just a keystroke away (`C-x C-e` in bash and zsh, in emacs-like line editing mode) if you have $EDITOR set properly.

1 more reply

zaptheimpaler12y ago

I think this approach is cleaner and you have the added advantage of having a permanent stash of useful commands you can move around systems.

Personally, I would use the hashtags, and also use something like inotify to automatically add any hashtagged commands to seperate scripts and store them in something like ~/usr/bin/custom/

pyre12y ago

It depends on how large your shell history is. I often have useful commands scrolled out of my history just because I got busy doing something orthogonal that involved a lot of shell commands.

samatman12y ago

What you are describing is persisting a command; the parent article describes a caching technique.

Caching a name for a command, as you issue it, makes it easier to retrieve later if you decide you want it as a proper script or alias. Among other things.

pyre12y ago· 1 in thread

The phplint example isn't a great one. If you use phplint enough you should either:

1) Create a generic shell script as others have stated.

2) Create a Makefile for your projects with a 'lint' target. If you create many different PHP projects, consider a project template directory with a Makefile that already has this, so that every new project automatically has the functionality:

  make lint

This idea has been around though. I can't recall if I've seen tagging used before, but saving an unexecuted commandline in the shell history by commenting it out is another useful hack that's been around a while.

scribu12y ago

The technique might have been around for a while, but it's the first time it made the connection in my head between twitter hashtags and bash comments, so +1 to the OP.

thejsjunky12y ago

For stuff like the example where you know you will be reusing the command, it's better to use an alias or script. Even if it's just a command you plan to run in a couple times in a row you can add a temporay alias with: alias foo = "!!" - that way you don't have to hit ctrl+r each time.

Still, it's a good tip in terms of adding comments to unusual/confusing commands so when you go through your history you're not like "wtf was I doing here?" or if you unexpectedly need to recall it.

catenate12y ago

This response explains how I use Acme to store (and later modify) commands in files in each directory.

https://news.ycombinator.com/item?id=5566567

In addition, I wrote a generic tag-indexing tool (in Plan 9's rc and Inferno's sh) to find random bits of information (including commands) without caring where they live in my file hierarchy.

https://github.com/catenate/notabene

http://swtools.wordpress.com/2010/03/05/nb%E2%80%94search-an...

thedeer12y ago

This is neat! I appreciate using something like hashtags in an unexpected, but useful way. And as for the comments saying the example should just be put in a shell script, that's not really relevant at all. The article has nothing to do with the merits of simple shell scripts versus a fun and useful hack.

portmanteaufu12y ago

hee hee, "bashtags."

twic12y ago

This is a cute hack.

j / k navigate · click thread line to collapse

19 comments

15 comments · 7 top-level

mooism212y ago· 7 in thread

Or you could stick the command in a shell script.

  #!/bin/sh
  find . -iname '*.php' -print0 | xargs -0 -n1 php -l

Save it to ~/bin/phplint (you do have ~/bin in your PATH, right?), chmod +x it, check it in, and you have a new phplint command. No need to mess about with hashtags in your shell history.

Am I missing something?

twic12y ago

What you may be missing is the difference in length between:

  Create a file ~/bin/phplint
  Type out the shebang
  Copy the command from the terminal into the file
  Save the file
  chmod +x the file

And:

  type #phplint

I'm sure Mr Venkat wouldn't claim that he has rendered script directories overnight. But he has come up with a way to make your shell history a little more usable.

mooism212y ago

You're right, the first alternative is disgustingly long-winded. Let's automate it.

Create a new shell script called `empty` somewhere on your PATH:

  #!/bin/bash
  set -e
  exec >"$1"
  printf '#!'
  which "$2"
  chmod +x "$1"
  cat

Next, add a new shell function to your ~/.bashrc:

  save-history() {
    history -p "$1" | empty ~/bin/"$2" bash
  }

To save the most recent command in your history to a shell script called ~/bin/phplint, run

  save-history '!!' phplint

You have to single-quote the '!!'; sorry about that. I'm using bash; maybe zsh has some way of making this easier to use.

1 more reply

ibotty12y ago

drdaeman12y ago

> not good enough to open an editor for

It's just a keystroke away (`C-x C-e` in bash and zsh, in emacs-like line editing mode) if you have $EDITOR set properly.

1 more reply

zaptheimpaler12y ago

I think this approach is cleaner and you have the added advantage of having a permanent stash of useful commands you can move around systems.

Personally, I would use the hashtags, and also use something like inotify to automatically add any hashtagged commands to seperate scripts and store them in something like ~/usr/bin/custom/

pyre12y ago

It depends on how large your shell history is. I often have useful commands scrolled out of my history just because I got busy doing something orthogonal that involved a lot of shell commands.

samatman12y ago

What you are describing is persisting a command; the parent article describes a caching technique.

Caching a name for a command, as you issue it, makes it easier to retrieve later if you decide you want it as a proper script or alias. Among other things.

pyre12y ago· 1 in thread

The phplint example isn't a great one. If you use phplint enough you should either:

1) Create a generic shell script as others have stated.

  make lint

scribu12y ago

The technique might have been around for a while, but it's the first time it made the connection in my head between twitter hashtags and bash comments, so +1 to the OP.

thejsjunky12y ago

Still, it's a good tip in terms of adding comments to unusual/confusing commands so when you go through your history you're not like "wtf was I doing here?" or if you unexpectedly need to recall it.

catenate12y ago

This response explains how I use Acme to store (and later modify) commands in files in each directory.

https://news.ycombinator.com/item?id=5566567

In addition, I wrote a generic tag-indexing tool (in Plan 9's rc and Inferno's sh) to find random bits of information (including commands) without caring where they live in my file hierarchy.

https://github.com/catenate/notabene

http://swtools.wordpress.com/2010/03/05/nb%E2%80%94search-an...

thedeer12y ago

portmanteaufu12y ago

hee hee, "bashtags."

twic12y ago

This is a cute hack.

j / k navigate · click thread line to collapse