Hello!
I want to evaluate some mathematical expressions in a script and I try to use 'expr' command.
Unfortunatally, when I have, for example,
expr 8.2 + 6
the result is 'expr: non-numeric argument'
Why ?
I work on SunOs 5.7.
Thanks in advance
Nathe (5 Replies)
What is the difference between test expr VS .
For example :
if test 5 -eq 6
echo "Wrong"
and
if
echo "Wrong"
bot will give the same output as Wrong.
Now, what is the difference between these two? though they are producing the same result why we need two?
Any answer will be... (2 Replies)
I'm trying to check if a variable'd string is only one character and use that in an if statement the only way I could find is:
$expr "${var}" : . # expr STRING : regrep
where the "." is the grep wildcard for any single character.
Whats wrong with my code here and is there a... (3 Replies)
$ cat > mtable
#!/bin/sh
#
#Script to test for loop
#
#
if
then
echo "Error - Number missing form command line argument"
echo "Syntax : $0 number"
echo "Use to print multiplication table for given number"
exit 1
fi
n=$1
for i in 1 2 3 4 5 6 7 8 9 10
do
echo "$n * $i = `expr $i \*... (1 Reply)
Hey there
i want to subtract the content from $b from $a. Each variable has got 18 values (normal numbers from 0 - 99).
How can i subtract them? I know i have to use the expr command, this is what i have till now:
a=`cat Tabelle.dat | awk {'print $4'} | awk -F: {'print $1'}`
b=`cat... (1 Reply)
Hi All,
I'm writing a shell script in KSH, where I want to store the filename, total record count and actual record count of all the source files. The source files reside in 4 different sub-folders under the same root folder.
Below is code:
#!/usr/bin/ksh... (6 Replies)
HI there
I am trying to understand Shell scripting to create my own, I am attempting a few examples can anyone tell me what this means?n=$( expr $n + 1)Tried looking on the internet, but just cannot find its anywhere :( .Help please (4 Replies)
Discussion started by: steve2015
4 Replies
LEARN ABOUT ULTRIX
expr
expr(1) General Commands Manual expr(1)Name
expr - evaluate expressions
Syntax
expr arg...
Description
The arguments are taken as an expression. After evaluation, the result is written on the standard output. Each token of the expression is
a separate argument.
The operators and keywords are listed below. The list is in order of increasing precedence, with equal precedence operators grouped.
expr | expr Yields the first expr if it is neither null nor 0. Otherwise yields the second expr.
expr & expr Yields the first expr if neither expr is null or 0. Otherwise yields 0.
expr relop expr The relop is one of < <= = != >= > and yields 1 if the indicated comparison is true, '0' if false. The comparison is
numeric if both expr are integers, otherwise lexicographic.
expr + expr
expr - expr
Yields addition or subtraction of the arguments.
expr * expr
expr / expr
expr % expr
Yields multiplication, division, or remainder of the arguments.
expr : expr The matching operator compares the string first argument with the regular expression second argument; regular expres-
sion syntax is the same as that of The (...) pattern symbols can be used to select a portion of the first argument.
Otherwise, the matching operator yields the number of characters matched ('0' on failure).
( expr ) parentheses for grouping.
Examples
The first example adds 1 to the Shell variable a:
a=`expr $a + 1`
The second example finds the file name part (least significant part) of the pathname stored in variable a,
expr $a : '.*/(.*)' '|' $a
Note the quoted Shell metacharacters.
Diagnostics
The command returns the following exit codes:
0 The expression is neither null nor '0'.
1 The expression is null or '0'.
2 The expression is invalid.
See Alsoed(1), sh(1), test(1)expr(1)