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Full Discussion: String Arithmetic ?
Top Forums UNIX for Dummies Questions & Answers String Arithmetic ? Post 302336754 by hkansal on Wednesday 22nd of July 2009 06:05:17 PM
Old 07-22-2009
String Arithmetic ?

Hello Experts,

In my shell I need to perform some simple subtraction on a value returned as a result of the "wc" command. The code:

Code:
scanFromLine="100"  ## This is returned as string as a result of some operation

totalLines=`wc -l "${latestLogFile}" | awk '{print $1}'` ## eg: 200

scanFromLine=`$(( ${totalLines} - ${scanFromLine} ))` ## this line throws an error

The error that I get is:
Code:
h1[227]: 200:  not found.

I am very positive that the error is not thrown because of the values being string. Please tell me my mistake here.

Regards,
HKansal
 

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PS_LINETO(3)								 1							      PS_LINETO(3)

ps_lineto - Draws a line

SYNOPSIS
bool ps_lineto (resource $psdoc, float $x, float $y) DESCRIPTION
Adds a straight line from the current point to the given coordinates to the current path. Use ps_moveto(3) to set the starting point of the line. PARAMETERS
o $psdoc - Resource identifier of the postscript file as returned by ps_new(3). o $x - x-coordinate of the end point of the line. o $y - y-coordinate of the end point of the line. RETURN VALUES
Returns TRUE on success or FALSE on failure. EXAMPLES
Example #1 Drawing a rectangle <?php $ps = ps_new(); if (!ps_open_file($ps, "rectangle.ps")) { print "Cannot open PostScript file "; exit; } ps_set_info($ps, "Creator", "rectangle.php"); ps_set_info($ps, "Author", "Uwe Steinmann"); ps_set_info($ps, "Title", "Lineto example"); ps_begin_page($ps, 596, 842); ps_moveto($ps, 100, 100); ps_lineto($ps, 100, 200); ps_lineto($ps, 200, 200); ps_lineto($ps, 200, 100); ps_lineto($ps, 100, 100); ps_stroke($ps); ps_end_page($ps); ps_delete($ps); ?> SEE ALSO
ps_moveto(3). PHP Documentation Group PS_LINETO(3)
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