If I understood your situation correctly, I believe the solution is to use eval to pass the result of the command substitution though the shell's parser.
I'm using an old version of bash which does not support "set -A", so I'm using positional parameters instead of an array variable to try and explain myself. The principles involved are identical. Hopefully, I am able to get my point across
Code:
$cat eval.sh
# The goal is to assign the value of $first to $1
# and the value of $second to $2.
first='$second' second='boo far'
# 1)
# This first example exhibits the problem you are
# experiencing. The quotes intended to delimit the
# string are taken as part of the string itself,
# since command substitution occurs after the parsing
# step which cares about quoting.
set -- `echo \"$first\" \"$second\"`
echo "First positional parameter: $1"
echo "Second positional parameter: $2"
# Outputs:
# First positional parameter: "$second"
# Second positional parameter: "boo
# -----------------------------------------
# 2)
# Adding eval passes the result from command substitution
# through the parser, and the quotes are indeed interpreted
# as you'd like. However, with weak double quotes, if
# there is anything in the substituted text that would
# cause the shell to attempt parameter/command substitution,
# the output will be undesirably affected. In this case, the
# value of $first, the string "$second", is taken as a parameter
# which is then substituted, resulting in the value of $1
# being identical to that of $2.
eval set -- `echo \"$first\" \"$second\"`
echo "First positional parameter: $1"
echo "Second positional parameter: $2"
# Outputs:
# First positional parameter: boo far
# Second positional parameter: boo far
# -----------------------------------------
# 3)
# The correct solution is wrap the command substituted values
# in strong quotes, to ensure that they are taken literally and
# not word split when passed through the parser a second time.
eval set -- `echo \'$first\' \'$second\'`
echo "First positional parameter: $1"
echo "Second positional parameter: $2"
# Finally, the correct output:
# First positional parameter: $second
# Second positional parameter: boo far
Hope this helped,
alister
Last edited by alister; 01-04-2010 at 10:52 PM..
Reason: typos
Hi,
Please can someone help to return the array elements from a function. Currently the problem I face is that tempValue stores the value in myValue as a string while I need an array of values to be returned instead of string.
Many Thanks,
Sudhakar
the function called is:
... (5 Replies)
I would like to find a list of files in a directory less than 2 days old and put them into an array variable. And then search for each file in the array for a matching string say "Return-code= 0". If it matches, then display the array element with a message as "OK".
Your help will be greatly... (1 Reply)
Hi,
My doubt is how to access array elements..
Situation is as below:
#!/bin/ksh
set -x
typeset -i x=0
typeset -i y=0
typeset -i BID=0
typeset -i count=0
while ] ; do
x=`expr $x + 1`;
hwmgr show scsi > scsi.tmp
while read line; do
set... (1 Reply)
Is there a way to print multiple array elements without iterating through the array using bash?
Can you do something like...
echo ${array}and get all those separate elements from the array? (2 Replies)
Hi I have two arrays :
@arcb= (450,625,720,645);
@arca=(625,645);
I need to remove the elements of @arca from elements of @arcb so that the content of @arcb will be (450,720).
Can anyone sugget me how to perform this operation?
The code I have used is this :
my @arcb=... (3 Replies)
I have a script which takes backup of some configuration files on my server. It does that by using an array which contains the complete path to the files to backup.
It copys the files to a pre defined dir. Each "program" has it's own folder, ex. apache.conf is being copied to /predefined... (7 Replies)
Hi,
I can't find out how to create correct code to get multiplication of each elements of array. Let's say I enter array into command line (2 3 4 5 6 8) and i need output 2*3*4*5*6*8=5760.
I tried this one, but answer is 0.
for i in $@; do
mult=$((mult*i))done
echo "mult: " $mult
... (4 Replies)
Hi
I wanted to print random elements from an array at bash shell
I use the following code, but I always see first element getting printed
#!/bin/bash
c=1
expressions=(pink red white yellow purple)
while ]; do
echo "The value of RANDOM is $RANDOM"
selectedexpression=${expressions}]};... (5 Replies)
Hi All,
need help with reading the array and sum of the array elements.
given an array of integers of size N . You need to print the sum of the elements in the array, keeping in mind that some of those integers may be quite large.
Input Format
The first line of the input consists of an... (1 Reply)
I have an array code and output is below:
echo $1
while read -r fline; do
echo "%%%%%%$fline%%%%%"
fmy_array+=("$fline")
done <<< "$1"
Output:
CR30903 YU0007 SRIL CR30903 Yogesh SRIL
%%%%%%CR30903 YU0007 SRIL%%%%%
%%%%%%CR30903 Yogesh SRIL%%%%%
... (8 Replies)
Discussion started by: mohtashims
8 Replies
LEARN ABOUT DEBIAN
dlas2
dlas2.f(3) LAPACK dlas2.f(3)NAME
dlas2.f -
SYNOPSIS
Functions/Subroutines
subroutine dlas2 (F, G, H, SSMIN, SSMAX)
DLAS2
Function/Subroutine Documentation
subroutine dlas2 (double precisionF, double precisionG, double precisionH, double precisionSSMIN, double precisionSSMAX)
DLAS2
Purpose:
DLAS2 computes the singular values of the 2-by-2 matrix
[ F G ]
[ 0 H ].
On return, SSMIN is the smaller singular value and SSMAX is the
larger singular value.
Parameters:
F
F is DOUBLE PRECISION
The (1,1) element of the 2-by-2 matrix.
G
G is DOUBLE PRECISION
The (1,2) element of the 2-by-2 matrix.
H
H is DOUBLE PRECISION
The (2,2) element of the 2-by-2 matrix.
SSMIN
SSMIN is DOUBLE PRECISION
The smaller singular value.
SSMAX
SSMAX is DOUBLE PRECISION
The larger singular value.
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
November 2011
Further Details:
Barring over/underflow, all output quantities are correct to within
a few units in the last place (ulps), even in the absence of a guard
digit in addition/subtraction.
In IEEE arithmetic, the code works correctly if one matrix element is
infinite.
Overflow will not occur unless the largest singular value itself
overflows, or is within a few ulps of overflow. (On machines with
partial overflow, like the Cray, overflow may occur if the largest
singular value is within a factor of 2 of overflow.)
Underflow is harmless if underflow is gradual. Otherwise, results
may correspond to a matrix modified by perturbations of size near
the underflow threshold.
Definition at line 108 of file dlas2.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.1 Sun May 26 2013 dlas2.f(3)
01-04-2010
