09-25-2008
brackets vs parentheses - single and double
hi, unix gurus.
i am wondering if someone can give me a clear explanation of the differneces between parentheses and brackets, both single and double.
i have heard that double parentheses (( are used for numerical expressions and that single brackets [ are used for strings. but i see very different behavior on this forum and elsewhere. i would love some clarity!
thanks for your help as usual.
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
i m trying the following command but its not working:
sed 's/find/\'replace\'/g' myFile
but the sed enters into new line
# sed 's/find/re\'place/g' myFile
>
I havn't any idea how to put single quote in my replace string. Your early help woud be appreciated. Thanx (2 Replies)
Discussion started by: asami
2 Replies
2. UNIX for Dummies Questions & Answers
what is the rationale behind putting double square brackets in an if clause?
for e.g.
if ] || ] || ];
then
echo some fields are null
fi (5 Replies)
Discussion started by: napolayan
5 Replies
3. Shell Programming and Scripting
One of the senior administrators gave me a shell script to modify and it begins as follows:
if ] && ]
{more code follows}
Why the double square brackets? (10 Replies)
Discussion started by: mojoman
10 Replies
4. Shell Programming and Scripting
Hi
First apologies if this has been raised before.
I've got the following in a ksh script:
if ]
For some reason this does not work. But if I remove the double square brackets to:
if
This works.
I thought ksh supported the ]. Or is there more to it?
Thanks in advance. (3 Replies)
Discussion started by: tsu3000
3 Replies
5. Shell Programming and Scripting
Dear All,
Recently got some sample from internet search for array handle in shell script, and I can not understand why we need to put double brackets when extracting array values by this way :
for ((i=0; i<${#admins}; i++)); do
echo "${admins}"
done
if modify from double to single... (2 Replies)
Discussion started by: tiger2000
2 Replies
6. Shell Programming and Scripting
Hi,
I just came across an interesting shell script syntax like the one below:
] && (trap 'rm -rf ${WORK_DIR}/*.$$; echo "\n\nInterrupted !!\n\n"; exit 4' 1 2 3 15)
Can someone please explain the code snippet above?
The trap command bit is fine but ] && is the hazy part.
Generally we use an... (2 Replies)
Discussion started by: King Nothing
2 Replies
7. UNIX for Dummies Questions & Answers
Hello,
I have done a great deal of research on this and still cannot come to an understanding of the following:
In if-else statements in shell scripting I have seen examples of single brackets, double brackets, single parantheses, and double paratheses. When should each one be used?
And... (2 Replies)
Discussion started by: mojoman
2 Replies
8. Shell Programming and Scripting
Hi.could you explain me what are the rules when we are using double parentesis in if statement,if I put ,the code is working ,with (( is not
#!/bin/bash
if (($# > 0))
then
if ((! -d "$1"))
then
echo "Directory $1 not found"
fi
else
echo Problem
fi (8 Replies)
Discussion started by: lio123
8 Replies
9. UNIX for Dummies Questions & Answers
Hi frieds, I don't understand the difference between single square bracket and double square brackets in a IF condition.
Ex.
if ;
then
RETURNJOB=1
else
RETURNJOB=0
fi
It run, but this
if ];
then
RETURNJOB=1
else
RETURNJOB=0
fi (4 Replies)
Discussion started by: dogshort
4 Replies
10. Shell Programming and Scripting
Hi Froum.
I have tried in vain to find a solution for this problem - I'm trying to replace any double quotes within a quoted string with a single quote, leaving everything else as is.
I have the following data:
Before:
... (32 Replies)
Discussion started by: pchang
32 Replies
LEARN ABOUT SUSE
pango::matrix
Pango::Matrix(3) User Contributed Perl Documentation Pango::Matrix(3)
NAME
Pango::Matrix
HIERARCHY
Glib::Boxed
+----Pango::Matrix
METHODS
matrix = Pango::Matrix->new ($xx=1., $xy=0., $yx=0., $yy=1., $x0=0., $y0=0.)
o $xx (double)
o $xy (double)
o $yx (double)
o $yy (double)
o $x0 (double)
o $y0 (double)
$matrix->concat ($new_matrix)
o $new_matrix (Pango::Matrix)
$matrix->rotate ($degrees)
o $degrees (double)
$matrix->scale ($scale_x, $scale_y)
o $scale_x (double)
o $scale_y (double)
(dx, dy) = $matrix->transform_distance ($dx, $dy)
o $dx (double)
o $dy (double)
Since: pango 1.16
array reference = $matrix->transform_pixel_rectangle ($rect)
o $rect (array reference)
Since: pango 1.16
(x, y) = $matrix->transform_point ($x, $y)
o $x (double)
o $y (double)
Since: pango 1.16
array reference = $matrix->transform_rectangle ($rect)
o $rect (array reference)
Since: pango 1.16
$matrix->translate ($tx, $ty)
o $tx (double)
o $ty (double)
double = $matrix->x0 ($new)
o $new (double)
double = $matrix->xx ($new=0)
o $new (double)
double = $matrix->xy ($new)
o $new (double)
double = $matrix->y0 ($new)
o $new (double)
double = $matrix->yx ($new)
o $new (double)
double = $matrix->yy ($new)
o $new (double)
SEE ALSO
Pango, Glib::Boxed
COPYRIGHT
Copyright (C) 2003-2009 by the gtk2-perl team.
This software is licensed under the LGPL. See Pango for a full notice.
perl v5.12.1 2010-07-05 Pango::Matrix(3)