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4.10 Find All Command Versions with whereiz

To get the absolute pathname of a command, Korn shell users can run whence . bash users have type . On other shells, use which (50.8 ) . But those will only show the first directory in your PATH (6.4 ) with that command. If you want to find other commands with the same name in other directories, the standard which won't show them to you. (The which on the CD-ROM will - if you use its  - a option. So will the bash command type -all .) whereiz will:

% which grep


/usr/bin/grep
% whereiz grep


/usr/bin/grep /usr/5bin/grep

On my system, the /usr/bin directory holds a Berkeley-like version of a command. The /usr/5bin directory holds System V versions. /usr/bin is first in my path, but it's good to know if there's also a System V version. whereiz also lets you see if there are both local and system versions of the same command in your path.

Here's the script. The name ends in a z because many UNIX versions already have a whereis (50.5 ) command.



















&&
 






#! /bin/sh

# COMMAND THAT TESTS FOR EXECUTABLE FILES... SYSTEM-DEPENDENT:
testx="test -x"

# REPLACE NULL FIELD IN $PATH WITH A .
fixpath="`echo $PATH | sed \
    -e 's/^:/.:/' \
    -e 's/::/:.:/g' \
    -e 's/:$/:./'`"

IFS=":  "       # SET $IFS (COLON, SPACE, TAB) FOR PARSING $PATH
for command
do
    where=""            # ZERO OUT $where

    # IF DIRECTORY HAS EXECUTABLE FILE, ADD IT TO LIST: 
    for direc in $fixpath
    do $testx $direc/$command && where="$where $direc/$command" 
    done

    case "$where" in
    ?*) echo $where ;;  # IF CONTAINS SOMETHING, OUTPUT IT
    esac
done

The sed (34.24 ) command "fixes" your PATH . It replaces a null directory name (:: in the middle of the PATH or a single : at the start or end of the PATH ), which stands for the current directory. The null member is changed to the relative pathname for the current directory, a dot (1.21 ) , so the direc shell variable in the loop won't be empty. In line 12, the double quotes ("" ) have colon, space, and tab characters between them. This sets the IFS (35.21 ) variable to split the "fixed" search path, at the colon characters, into separate directories during the for loop (44.16 ) . That's a useful way to handle any colon-separated list.

- JP


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