Is there a way to create an temporary aliases, mainly to cut down typing dir paths, especially those not used as often to warrant adding to .bash_aliases?
Thanks
Just type one in.
94 $ alias hello='echo hello'
95 $ hello
hello
You can type
long=~/long/path/to/a/directory
and use it as
cd ~long
(just add tilde to the beginning).
You will also see "~long" in your prompt instead of the full path.
Related
If I try
$ alias pwd=echo
$ alias echo=pwd
I get
$ pwd
/home/owen
$ echo hi
hi
It seems aliases are followed recursively. Perhaps if there was a way to stop the recursion, that would work. In this example I can use builtin, but that won't work in general, particular for -g aliases.
All you want is that your commands are expanded once.
As describe in the zsh documentation; you can prevent an alias expansion by quoting.
This should do the trick
$ alias pwd="\echo" ; alias echo="\pwd"
There are two ways to do the equivalent of using builtin for commands which aren't built-in shell commands
The first is to just use the full path for the command you get from which. For example,
> which cat
/bin/cat
> /bin/cat
will run cat, ignoring any alias you may have set up.
The other option is to use /usr/bin/env. For example,
> /usr/bin/env cat
will also run cat while ignoring any alias to cat you may have set up.
Is there a standard way in a unixesque (sh/bash/zsh) system to execute a group of scripts as if the group of scripts was one script? (Think index.html). The point is to avoid additional helper scripts like you usually find and keep small programs self sufficient and easier to maintain.
Say I have two (in bold) ruby scripts.
/bin /bin/foo_master /bin/foo_master/main
/bin/foo_master/helper.rb
So now when I execute foo_master
seo#macbook ~ $foo_master [/bin/foo_master/main]: Make
new friends, but keep the old. [/bin/foo_master/helper.rb]: One
is silver and the other gold.
If you're trying to do this without creating a helper script, the typical way to do this would just be to execute both (note: I'll use : $; to represent the shell prompt):
: $; ./main; ./helper.rb
Now, if you're trying to capture the output of both into a file, say, then you can group these into a subshell, with parenthesis, and capture the output of the subshell as if it was a single command, like so:
: $; (./main; ./helper.rb) > index.html
Is this what you're after? I'm a little unclear on what your final goal is. If you want to make this a heavily repeatable thing, then one probably would want to create a wrapper command... but if you just want to run two commands as one, you can do one of the above two options, and it should work for most cases. (Feel free to expand the question, though, if I'm missing what you're after.)
I figured out how to do this in a semi-standard complaint fashion.
I used the eval syntax in shell scripting to lambda evaluate the $PATH at runtime. So in my /etc/.zshrc
$REALPATH = $PATH
$PATH = $REALPATH:`find_paths`
where find_paths is a function that recursively searches the $PATH directories for folders (pseudocode below)
(foreach path in $PATH => ls -d -- */)
So we go from this:
seo#macbook $ echo $PATH
/bin/:/usr/bin/
To this, automagically:
seo#macbook $ echo $PATH
/bin/:/usr/bin/:/bin/foo_master/
Now I just rename main to "foo_master" and voilà! Self contained executable, dare I say "app".
Yep that's an easy one!
#!/bin/bash
/bin/foo_master/main
/bin/foo_master/helper.rb
Save the file as foo_master.sh and type this in the shell:
seo#macbook ~ $sudo chmod +x foo_master.sh
Then to run type:
seo#macbook ~ $./foo_master.sh
EDIT:
The reason that an index.html file is served at any given directory is because the HTTP Server explicitly looks for one. (In server config files you can specify names of files to look for to server like index.html i.e. index.php index.htm foo.html etc). Thus it is not magical. At some point, a "helper script" is explicitly looking for files. I don't think writing a script like above is a step you can skip.
Is there a way in a unix shell (specifically Ubuntu) to change directory into the xth directory that was printed from the ls command?
I know you can sort a directory in multiple ways, but using the output from ls to get the xth directory?
An example shell:
$ ls
$ first_dir second_dir third_really_long_and_complex_dir
where I want to move into the third_really_long_and_complex_dir by passing 3 (or 2 in proper array format).
I know I could simply copy and paste, but if I'm already using the keyboard, it would be easier to type something like "cdls 2" or something like that if I knew the index.
The main problem with cd in an interactive session is that you generally want to change the current directory of the shell that is processing the command prompt. That means that launching a sub-shell (e.g. a script) would not help, since any cd calls would not affect the parent shell.
Depending on which shell you are using, however, you might be able to define a function to do this. For example in bash:
function cdls() {
# Save the current state of the nullglob option
SHOPT=`shopt -p nullglob`
# Make sure that */ expands to nothing when no directories are present
shopt -s nullglob
# Get a list of directories
DIRS=(*/)
# Restore the nullblob option state
$SHOPT
# cd using a zero-based index
cd "${DIRS[$1]}"
}
Note that in this example I absolutely refuse to parse the output of ls, for a number of reasons. Instead I let the shell itself retrieve a list of directories (or links to directories)...
That said, I suspect that using this function (or anything to this effect) is a very good way to set yourself up for an enormous mess - like using rm after changing to the wrong directory. File-name auto-completion is dangerous enough already, without forcing yourself to count...
Is there a way I can get the pwd in an alias in my .zshrc file? I'm trying to do something like the following:
alias cleanup="rm -Rf `pwd`/{foo,bar,baz}"
This worked fine in bash; pwd is always the directory I've cd'd into, however in zsh it seems that it's evaluated when the .zshrc file is first loaded and always stays as my home directory. I've tested using with a really simple alias setup, but it never changes.
How can I have this change, so that calling the alias from a subdirectory always evaluates as that subdir?
EDIT: not sure if this will help, but I'm using zsh via oh-my-zsh on the mac.
When your .zshrc is loaded, the alias command is evaluated. The command consists of two words: a command name (the builtin alias), and one argument, which is the result of expanding cleanup="rm -Rf `pwd`/{foo,bar,baz}". Since backquotes are interpolated between double quotes, this argument expands to cleanup=rm -Rf /home/unpluggd/{foo,bar,baz} (that's a single shell word) where /home/unpluggd is the current directory at that time.
If you want to avoid interpolation at the time the command is defined, use single quotes instead. This is almost always what you want for aliases.
alias cleanup='rm -Rf `pwd`/{foo,bar,baz}'
However this is needlessly complicated. You don't need `pwd/` in front of file names! Just write
alias cleanup='rm -Rf -- {foo,bar,baz}'
(the -- is needed if foo might begin with a -, to avoid its being parsed as an option to rm), which can be simplified since the braces are no longer needed:
alias cleanup='rm -Rf -- foo bar baz'
For my developer work I reside in the *nix shell environment pretty much all day, but still can't seem to memorize the name and argument specifics of programs I don't use daily. I wonder how other 'casual amnesiacs' handle this. Do you maintain an big cheat sheet? Do you rehearse the emacs shortcuts when you take your weekly shower? Or is your desk covered under sticky notes?
Using bash_completion is one way of not having to remember the precise syntax of program arguments.
> svn [tab][tab]
--help checkout delete lock pdel propget revert
--version ci diff log pedit proplist rm
-h cleanup export ls pget propset status
add co help merge plist pset switch
annotate commit import mkdir praise remove unlock
blame copy info move propdel rename update
cat cp list mv propedit resolved
If I don't use a command regularly enough to remember what I want, I tend to just use --help or the man pages when I need to.
Or, if I'm lucky, I use CTRL+R and let bash's history search find when I last used it.
Eventually you just remember them, well the set that you use anyway. I used to maintain a README in my home directory when I was starting out but that disappeared many years ago.
One useful command is man -k which you pass a word to and it will return a list of all commands whose man page summary contains that word.
'apropos' is also a very useful command. It will list all commands whose man pages contain the keyword.