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Tested with bash v4.1.5 on ubuntu 10.10
Limitations:
as written above, only works for programs with no file extention (i.e 'proggy', but not 'proggy.sh')
because \eb maps to readine function backward-word rather then shell-backward-word (which
is unbinded by default on ubuntu), and correspondingly for \ef.
if you're willing to have Ctrl-f and Ctrl-g taken up too , you can insert the following lines
into ~/.inputrc, in which case invoking Ctrl-e will do the right thing both for "proggy" and "proggy.sh".
-- cut here --
\C-f:shell-backward-word
\C-g:shell-forward-word
"\C-e":"\C-f`which \C-g`\e\C-e"
-- cut here --
This will show you any links that a command follows (unlike 'file -L'), as well as the ultimate binary or script.
Put the name of the command at the very end; this will be passed to perl as the first argument.
For obvious reasons, this doesn't work with aliases or functions.
I used to do a lot of path manipulation to set up my development environment (PATH, LD_LIBRARY_PATH, etc), and one part of my environment wasn't always aware of what the rest of the environment needed in the path. Thus resetting the entire PATH variable wasn't an option; modifying it made sense.
The original version of the functions used sed, which turned out to be really slow when called many times from my bashrc, and it could take up to 10 seconds to login. Switching to parameter substitution sped things up significantly.
The commands here don't clean up the path when they are done (so e.g. the path gets cluttered with colons). But the code is easy to read for a one-liner.
The full function looks like this:
remove_path() {
eval PATHVAL=":\$$1:"
PATHVAL=${PATHVAL//:$2:/:} # remove $2 from $PATHVAL
PATHVAL=${PATHVAL//::/:} # remove any double colons left over
PATHVAL=${PATHVAL#:} # remove colons from the beginning of $PATHVAL
PATHVAL=${PATHVAL%:} # remove colons from the end of $PATHVAL
export $1="$PATHVAL"
}
append_path() {
remove_path "$1" "$2"
eval PATHVAL="\$$1"
export $1="${PATHVAL}:$2"
}
prepend_path() {
remove_path "$1" "$2"
eval PATHVAL="\$$1"
export $1="$2:${PATHVAL}"
}
I tried using regexes to make this into a cleaner one-liner, but remove_path ended up being cryptic and not working as well:
rp() { eval "[[ ::\$$1:: =~ ^:+($2:)?((.*):$2:)?(.*):+$ ]]"; export $1=${BASH_REMATCH[3]}:${BASH_REMATCH[4]}; };
If I type 'man something', I want it to find the manpage in the same order as my PATH.
You can add something like this to your .bashrc
#
# Add my MacPorts, my personal utilities and my company utilities to my PATH.
export PATH=$PATH:/opt/local/bin:$HOME/bin:/our_company_utils/bin/
# Now set the manpath based on the PATH, after man(1) parses man.conf
# - No need to modify man.conf or manually modify MANPATH_MAP
# - Works on Linux, FreeBSD & Darwin, unlike /etc/manpaths.d/
# Must unset MANPATH first. MANPATH is set on some systems automatically (Mac),
# which causes manpath to ignore the values of PATH like /opt/local/bin (MacPorts).
# Also MANPATH may be deprecated. See "SEARCH PATH FOR MANUAL PAGES" in man(1)
unset MANPATH
# manpath acts differently on Solaris, FreeBSD, MacOSX & GNU. This works everywhere.
manpath >/dev/null
#
Note that MacOSX, FreeBSD & Linux have fancier ways to do some of this. (e.g. 'man --path' or 'man -q'), but this command is more universal and should work everywhere.
i.e.: Useful if you add ~/bin to your $PATH and you want to override locations of previously ran commands and you don't want to log out and log back in to be able to use them.
The wherepath function will search all the directories in your PATH and print a unique list of locations in the order they are first found in the PATH. (PATH often has redundant entries.) It will automatically use your 'ls' alias if you have one or you can hardcode your favorite 'ls' options in the function to get a long listing or color output for example.
Alternatives:
'whereis' only searches certain fixed locations.
'which -a' searches all the directories in your path but prints duplicates.
'locate' is great but isn't installed everywhere (and it's often too verbose).
On RHEL, Fedora and CentOS systems, and maybe others, the sbin directories aren't in the user's $PATH. For those systems that use 'sudo', this can be inconvenient typing the full path all the time. As a result, you can easily take advantage of adding the sbin directories to your PATH by adding this simple line to you .zshrc.
Another way of doing it that's a bit clearer. I'm a fan of readable code.
I often need to know of my directory in the PATH, which one DOES NOT exist. This command answers that question
* This command uses only bash's built-in commands
* The parentheses spawn a new sub shell to prevent the modification of the IFS (input field separator) variable in the current shell
Finds executable and existing directories in your path that can be useful if migrating a profile script to another system. This is faster and smaller than any other method due to using only bash builtin commands.
See also:
+ http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html