Understanding $PATH better Post: 302949750

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Top Forums Shell Programming and Scripting Understanding $PATH better Post 302949750 by Don Cragun on Wednesday 15th of July 2015 02:43:19 PM

07-15-2015

Registered User

Quote:

Originally Posted by sea

Also, your (custom modified) $PATH looks VERY limited, will it find find, ls, grep, awk or even your shell?
With that $PATH, it wont find any of these, if they are at their regular locations. (edit: scratch that, just seen you had /bin, though, that might - but not granted - contain all the binaries required)

For the future, try:

Code:

PATH+=":/my_data/execs:/universal/execs/:/newpath/configure/:/test_dir/"

Note the + before the =!

AFAIK, its a bad habbit to 'overwrite' $HOME with a custom location such as /home/execs/testing.
I'd recomend to set a new/other variable, and call it like, BASE or base or even more appropriate: WORKDIR=/home/execs/testing.

hth

sea is absolutely correct about not messing with HOME.

While += works in some shells, it doesn't work on some. (For example, /bin/sh on Solaris systems won't accept it.) The standard way to do it (supported by all shells based on Bourne shell syntax) would be:

Code:

PATH="$PATH:/my_data/execs:/universal/execs:/newpath/configure:/test_dir"

Note that the trailing slashes aren't needed; any element in the list of directories in PATH that isn't a directory will fail when attempting to add a command name to it anyway.

If you were writing a shell script (or a C program) that is intended to run with set-UJID or set-GID privileges and your program runs anything not using an absolute pathname to invoke it, then you should provide a PATH variable that is know to find the "desired" version of any programs invoked (not something that could spoof a "standard" utility and grab extended privileges for use later), but that is a much more complicated topic that clearly does not apply to this script.

Don Cragun

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LEARN ABOUT DEBIAN

surfraw-update-path

SURFRAW-UPDATE-PATH(1)					User Contributed Perl Documentation				    SURFRAW-UPDATE-PATH(1)

NAME

       surfraw-update-path - updates PATH in shell config files

SYNOPSIS

       surfraw-update-path [-add] [-remove] [-check] [-sys] [-all] [-help] [-shell=SHELL]

DESCRIPTION

       surfraw-update-path adds the surfraw elvi directory (/usr/lib/surfraw) to your PATH in your shell's config file.

       Currently it supports bash, sh, csh, tcsh, ash, dash, ksh, pdksh, zsh, rc, and es

       Don't forget to login again or source your login files for it to take effect.

OPTIONS

       -check
	   Checks to see if the surfraw config code is present.  This is the default.

       -add
	   Adds the surfraw config code.

       -remove
	   Removes the surfraw config code

       -sys
	   Updates the system-wide shell config instead of the user.  Must be done as root.

       -shell=SHELL
	   Selects the shell to configure. Defaults to the value of the $SHELL environment variable.

	   Currently supported shells are:

	   sh, ash, bash, dash, csh, tcsh, ksh, pdksh, zsh, rc, and es.

       -all
	   Attempts to configure the startup files for all known shells

       -help
	   Gives a usage message

RETURN VALUE

       -check returns 0 if the surfraw code is present in the file, 1 if it is not found, or 2 on error.

       All other options return 0 on success, or 2 on error.

ENVIRONMENT

       SHELL
	   Used to determine which shell to configure, if -shell is not given.

       HOME
	   Used to find users config files.

       ENV Used by posix-compliant shells to specify a startup rc file.

       ZDOTDIR
	   Used to find user config files for zsh. If not set, defaults to HOME.

SEE ALSO

       surfraw(1), sh(1), ash(1), bash(1), dash(1), csh(1), tcsh(1), ksh(1), pdksh(1), zsh(1), rc(1), es(1)

AUTHOR

       Ian Beckwith <ianb@erislabs.net>

perl v5.12.4							    2011-07-12						    SURFRAW-UPDATE-PATH(1)

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