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Full Discussion: Use parameter expansion over a parameter expansion in bash.
Top Forums Shell Programming and Scripting Use parameter expansion over a parameter expansion in bash. Post 303043406 by RavinderSingh13 on Tuesday 28th of January 2020 01:31:44 AM
Old 01-28-2020
Use parameter expansion over a parameter expansion in bash.
Hello All,

Could you please do help me here as I would like to perform parameter expansion in shell over a parameter expansion.

Let's say I have following variable.
Code:
path="/var/talend/nat/cdc"

Now to get only nat I could do following.
Code:
path1="${path%/*}"
path1="${path1##*/}"

Here in this approach I am creating a temporary variable path1 and again performing parameter expansion, how about if I want to perform this in single time without having temporary variable? I have tried it like:

Code:
echo "${((${path%/*}))##*/}"

Which is giving me an error. Any help, guidance is appreciated.

Thanks,
R. Singh
This User Gave Thanks to RavinderSingh13 For This Post:
nezabudka
 

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LEARN ABOUT SUSE

mbk_cata_lib

MBK_CATA_LIB(1)                                              MBK ENVIRONMENT VARIABLES                                             MBK_CATA_LIB(1)

NAME

       MBK_CATA_LIB - define the mbk catalog directory

SYNOPSYS

       c-shell running
       setenv MBK_CATA_LIB path1:path2:path3:...:...:pathn

ORIGIN

       This  software  belongs  to  the  ALLIANCE CAD SYSTEM developed by the ASIM team at LIP6 laboratory of Universite Pierre et Marie CURIE, in
       Paris, France.

       Web : http://asim.lip6.fr/recherche/alliance/
       E-mail : alliance-users@asim.lip6.fr

DESCRIPTION

       MBK_CATA_LIB sets the directories that are to be searched thru for reading. When instanciating a cell for example, the first cell  that  is
       found with the given name is loaded in memory.
       The seaching mecanism first look in MBK_WORK_LIB(1), and then, in path1 thru pathn, in the order defined by the user when typing the setenv
       command.  This directories are considered to be, from a mbk point of view, read only.
       The pathi arguments must be actually accessible pathes on your host machine.

ERRORS

       "mbk_fopen : can't open file 'unix_path/file.xx' thru directories : path1, ..., pathn"
              This occurs when either the unix path is irrelevent, or when the file doesn't exist. This can also be a unix right  problem  if  the
              file is not accessible for reading, but this is seldom.

EXAMPLE

            setenv MBK_CATA_LIB ~fred/crechan/uom:/labo/sclib

DIAGNOSTICS

       Only the first path may be given with a '~', since the shell extents it only when seen first.

SEE ALSO

       mbk(3), genlib(1), MBK_WORK_LIB(1).

BUG REPORT

       This tool is under development at the ASIM department of the LIP6 laboratory.
       We need your feedback to improve documentation and tools.

ASIM
/LIP6                                                         October 1, 1997                                                  MBK_CATA_LIB(1)
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