Editing DotBashRc - CaffeinatedWiki

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My DotBashRc has been collecting more and more stuff for a while now.. every once in a while I just throw something new in when I do something for like the 10th time and realise that really, I could write a little function or alias and be lazier from then on. And laziness is good, believe me!

A function in bash is like a function in most other programming language. It can take parameters (which you access as {{$1}}, {{$2}}, etc.) and can have a return value (which must be an integer; 0 is used to indicate success). An alias in bash is really just a substitution. When you alias x to y, then every time you type x in a command to bash, it will replace it with y. That's how you have to think about it.

So, let's get on with it.. here's most of my DotBashRc. I've removed certain things that aren't relevant.
<code>
# Whee! vi-mode all the way!
set -o vi

# Some "typical" aliases. In fact, if you use RH, you probably don't need 'll'
alias users="who |awk '{print \$1}' |sort |uniq"
alias ll='ls -l'
alias vi=vim

# Useful for finding stuff in source
gsrc()
{
  grep -IE "$*" `find . -type f |grep -vE \
'(\.lo$|\.TPo$|\.dep$|\.\d$|CVS|\.mk$|Makefile|ChangeLog|cvsignore|\.in$|\.ac$|\.am$|\.#)'`
}
gsrci()
{
  grep -iIE "$*" `find . -type f |grep -vE \
'(\.lo$|\.TPo$|\.dep$|\.\d$|CVS|\.mk$|Makefile|ChangeLog|cvsignore|\.in$|\.ac$|\.am$|\.#)'`
}

# For moving a bunch of files, replacing one regex with another
plmv()
{
  local sub="s!$1!$2!"
  for i in *; do mv "$i" "$(echo "$i" |perl -pe "$sub")"; done
}
# Same as above, but you can specify a prefix for the files
plmvp()
{
  local sub="s!$2!$3!"
  for i in $1*; do mv "$i" "$(echo "$i" |perl -pe "$sub")"; done
}
# Check what sedmv would do
plchk()
{
  for i in *; do echo "$i" |perl -pe "s!$1!$2!"; done
}
# Check what sedmvp would do
plchkp()
{
  for i in $1*; do echo "$i" |perl -pe "s!$2!$3!"; done
}

# So I can edit .bashrc and do . !$ without re-updating my $PATH
if [ "`echo $PATH |grep sbin`" = "" ]; then
  export PATH=$PATH:/sbin:/usr/local/sbin:/usr/sbin
fi
</code>
Hmm.. so you look at that, and maybe it looks like a bunch of random garbage to you. But maybe after I explain what some of the neater things do, you'll be a bit more interested:

First, {{set -o vi}} puts the shell in {{vi}} mode. If you're not used to {{vi}}, or you're a beginner with Unix, you probably don't want this. If you've used {{vi}} for text editing before and you don't mind it, you might want to give it a shot.

Next, we have some aliases. I don't like the typical {{users}} command, so I alias my own to provide a nicer list. {{ll}} is set up out of the box on some distros, and just gives you a more detailed directory listing. Aliasing {{vi}} to {{vim}} ensures I always get {{vim}}, which has some niceties I prefer over plain {{vi}}.

The {{gsrc}} functions have definitely saved me lots of times. If you've ever worked on a fairly large development project, you know it can sometimes be a pain to find a certain function, or a certain peice of code you ''know'' you've seen, you just can't remember here. With {{gsrc}} and {{gsrci}}, this is considerably easier. These functions take a regular expression (egrep syntax) and search through all source files under the current directory, recursively. What's better about {{gsrc}} and {{gsrci}} as opposed to just doing something like {{grep -Ir regex *}} is that they attempt to cut out non-relevant files. I care about ''source'', dammit! I don't want autoconf/automake/CVS/whatever files getting in my way, and these functions try to cut out as much of crud as possible. Oh, and the difference between {{gsrc}} and {{gsrci}} is that {{gsrci}} is case-insensitive.

The {{sedmv}} and {{sedchk}} functions are also pretty cool, IMO. Most likely, you've been in a situation where you've had a bunch of files, all having something in their name. And you want to move them in such a way that that one thing is replaced with something else. So maybe you have some files {{foo1, foo2, foo3}} and you want to move them so that you get {{foo01, foo02, foo03}}. With {{sedmv}} and {{sedmvp}} you can! {{sedmv}} acts on all files in the current directory, and replaces the first regex (sed syntax) you give it with the second. So in the example I just gave, I could do {{sedmv foo foo0}} and I'd get what I want. Pretty nice, eh? I think so, anyway. It's definitely saved me a bunch of time before. {{sedmvp}} works like {{sedmv}}, except that it takes 3 parameters. The first is a prefix of the files you want to work on. So if I had some other files in that directory, and I only cared about moving the foo files, I could do {{sedmv foo foo foo0}}. Then files like {{barfoo}} wouldn't be moved to {{barfoo0}}.

{{sedchk}} shows you what the results of a {{sedmv}} will be. This is nice, and allows you to (hopefully) avoid screwing up. These functions are really convenient and quite powerful, but they can be a bit dangerous, so it's a good idea to use {{sedchk}} or {{sedchkp}} first!

Finally, I add the various {{sbin}} directories to my path. This makes using {{sudo}} a whole lot easier.

Enjoy!

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