09-06-2011
expr ?!
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 Tabelle.dat | awk {'print $4'} | awk -F: {'print $2'}`
result=`( expr $a - $b )`
echo "$result"
Example:
content of $a
4
7
13
15
...
content of $b
5
3
6
17
result has to be:
$bla1 - $bla2
4 - 5 = -1
7 - 3 = 4
13 - 6 = 7
15 - 17 = -2
....
I know i have to use a loop but i dont know how to put it in there...
I hope u can help me =)
mfg
Mad van Bert
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
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)
Discussion started by: Nathe
5 Replies
2. Shell Programming and Scripting
Hi,
in my ksh script
expr 22 / 10 results as 2
but the actual result expected in 2.2.
how do i get that result. Please help
Thanks, (2 Replies)
Discussion started by: kotasateesh
2 Replies
3. Shell Programming and Scripting
sum=0;
cat op_api2 |while read word1 word2;
do
echo $word2
sum=`expr $word2 + $sum`;
done
echo $sum
op_api2 ( file has this data )
----------------------------
UsageSummary 1034
UsageSummary 1675
UnbilledUsage 175
UnbilledUsage 177
UnbilledUsage 177
UnbilledUsage 194
I want the... (2 Replies)
Discussion started by: bishweshwar
2 Replies
4. Red Hat
i am new to shell programming, currently using redhat linux of version
2.4.20-8.
i have problem in executing expr command in the following shell script
$ x=5
$ x='expr $x + 1'
$ echo $x
the output is displaying always
expr $x + 1
Pls guide me for the above query (3 Replies)
Discussion started by: saikumarm80
3 Replies
5. Shell Programming and Scripting
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)
Discussion started by: ashok.g
2 Replies
6. Shell Programming and Scripting
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)
Discussion started by: Tewg
3 Replies
7. Shell Programming and Scripting
$ 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 $i \*... (1 Reply)
Discussion started by: jackel7777
1 Replies
8. Shell Programming and Scripting
Hi All,
I'm writing a shell script in KSH, where I want to store the filename, total record count and actual record count of all the source files. The source files reside in 4 different sub-folders under the same root folder.
Below is code:
#!/usr/bin/ksh... (6 Replies)
Discussion started by: jagari
6 Replies
9. Shell Programming and Scripting
Hi
I have bellow script:
t1=`cat node1.txt | grep thread1 | cut -f2 -d '-'`
t2=`cat node2.txt | grep thread2 | cut -f2 -d '-'`
t3=`cat node1_rcat.txt | grep thread1 | cut -f2 -d '-'`
t4=`cat node2_rcat.txt | grep thread2 | cut -f2 -d '-'`
if ]; then
echo "no restore" >> log.log... (6 Replies)
Discussion started by: primo102
6 Replies
10. Shell Programming and Scripting
HI there
I am trying to understand Shell scripting to create my own, I am attempting a few examples can anyone tell me what this means?n=$( 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 OPENSOLARIS
fmlexpr
fmlexpr(1F) FMLI Commands fmlexpr(1F)
NAME
fmlexpr - evaluate arguments as an expression
SYNOPSIS
fmlexpr arguments
DESCRIPTION
The fmlexpr function evaluates its arguments as an expression. After evaluation, the result is written on the standard output. Terms of the
expression must be separated by blanks. Characters special to FMLI must be escaped. Note that 30 is returned to indicate a zero value,
rather than the null string. Strings containing blanks or other special characters should be quoted. Integer-valued arguments may be pre-
ceded by a unary minus sign. Internally, integers are treated as 32-bit, 2s complement numbers.
The operators and keywords are listed below. Characters that need to be escaped are preceded by . The list is in order of increasing
precedence, with equal precedence operators grouped within {} symbols.
USAGE
Expressions
expr | expr
Returns the first expr if it is neither NULL nor 0, otherwise returns the second expr.
expr & expr
Returns the first expr if neither expr is NULL or 0, otherwise returns 0.
expr { =, >, >=, <, <=, != } expr
Returns the result of an integer comparison if both arguments are integers, otherwise returns the result of a lexical comparison.
expr { +, - } expr
Addition or subtraction of integer-valued arguments.
expr { *, /, % } expr
Multiplication, division, or remainder of the integer-valued arguments.
expr : expr
The matching operator : (colon) compares the first argument with the second argument which must be a regular expression. Regular
expression syntax is the same as that of ed(1), except that all patterns are "anchored" (that is, begin with ^) and, therefore, ^ is
not a special character, in that context. Normally, the matching operator returns the number of bytes matched (0 on failure). Alterna-
tively, the (...) pattern symbols can be used to return a portion of the first argument.
EXAMPLES
Example 1 Incrementing a variable
Add 1 to the variable a:
example% fmlexpr $a + 1 | set -l a
Example 2 Setting a variable equal to a filename
For $a equal to either /usr/abc/file or just file:
example% fmlexpr $a : .*/(.*) | $a
returns the last segment of a path name (that is, file). Watch out for / alone as an argument: fmlexpr will take it as the division opera-
tor (see NOTES below).
Example 3 A better representation of Example 2
example% fmlexpr //$a : .*/(.*)
The addition of the // characters eliminates any ambiguity about the division operator (because it makes it impossible for the left-hand
expression to be interpreted as the division operator), and simplifies the whole expression.
Example 4 Counting characters in a variable
Return the number of characters in $VAR:
example% fmlexpr $VAR : .*
EXIT STATUS
As a side effect of expression evaluation, fmlexpr returns the following exit values:
0 if the expression is neither NULL nor 0 (that is, TRUE)
1 if the expression is NULL or 0 (that is, FALSE)
2 for invalid expressions (that is, FALSE).
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO
ed(1), expr(1), set(1F), sh(1), attributes(5)
DIAGNOSTICS
syntax error for operator/operand errors
non-numeric argument if arithmetic is attempted on such a string
In the case of syntax errors and non-numeric arguments, an error message will be printed at the current cursor position. Use refresh to
redraw the screen.
NOTES
After argument processing by FMLI, fmlexpr cannot tell the difference between an operator and an operand except by the value. If $a is an
=, the command:
example% fmlexpr $a = =
looks like:
example% fmlexpr = = =
as the arguments are passed to fmlexpr (and they will all be taken as the = operator). The following works, and returns TRUE:
example% fmlexpr X$a = X=
SunOS 5.11 5 Jul 1990 fmlexpr(1F)