Using the C Shell, I'm building a script that will compute simple mathematical computations (addition, subtraction, multiplication, division). The user will enter two integers (operands) on the command line separated by the operation (operator) they wish to perform.
Example of the command line would be as follows: ./scriptname 5 minus 2
I have that part working perfectly. Where I'm running into a problem is the following:
1) If the any of the operands or operator are missing from the command line I want to print an error
2) If the user enters an invalid operator (not +, -, %, X) the script shall will print an error)
I've attached my script below. If you have any recommendations for the above two issues your help would be greatly appreciated. Thank you!
Code:
if ( $2 =~ "plus" ) then
@ c = $1 + $3
echo "The sum is: $c"
else if ( $2 =~ "minus" ) then
@ c = $1 - $3
echo "The difference is: $c"
else if ( $2 =~ "div" ) then
@ c = $1 / $3
echo "The quotient is: $c"
else if ( $2 =~ "times" ) then
@ c = $1 * $3
echo "The product is: $c"
else if ( ( $2 !~ "plus" || $2 !~ "minus" ) && ( $2 !~ "div" || $2 !~ "times" ) ) then
echo "You have entered an invalid operation"
else
echo "You are missing an operand or operator"
endif
I have an extraordinary problem with a csh script.....(feel free to berate the use of this but I'm modifying an existing bunch of them)
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Hi everyone,
I have never wrote script in csh before, but I need to add only few lines to an existing one. I tried to use the bash standard syntax, and it did not work. So, I attempted to use csh syntax, and it is not working. Can someone help please:
switch ( $Return_Code )
case 0:... (3 Replies)
Ok I asked something similar earlier with no response, so maybe I didn't word it correctly. I'm new at this, so thank you for your help.
Here's what I have right now.
----------------------------
> cat MySourceFile
#!/bin/csh
echo "Please Enter Value For My_Env_Var:"
set answer = $<
... (1 Reply)
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so just spit ballin here,
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Hello, I'm in need with a little help for my script please this is the brief i need to complete which I haven't been able to do:
On option 7 stop the calculator
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Pls any help... (1 Reply)
Hello, I have to make a calculator in shell script. But I get this error. Can someone help me please?
c.sh: 3: c.sh: i: not found
That's my code.
==========================================================================
#Calculator
i = "yes"
while
do
echo What operation... (2 Replies)
Discussion started by: KJN
2 Replies
LEARN ABOUT V7
expr
EXPR(1) General Commands Manual EXPR(1)NAME
expr - evaluate arguments as an expression
SYNOPSIS
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
where relop is one of < <= = != >= >, 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
addition or subtraction of the arguments.
expr * expr
expr / expr
expr % expr
multiplication, division, or remainder of the arguments.
expr : expr
The matching operator compares the string first argument with the regular expression second argument; regular expression syntax is
the same as that of ed(1). 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:
To add 1 to the Shell variable a:
a=`expr $a + 1`
To find the filename part (least significant part) of the pathname stored in variable a, which may or may not contain `/':
expr $a : '.*/(.*)' '|' $a
Note the quoted Shell metacharacters.
SEE ALSO ed(1), sh(1), test(1)DIAGNOSTICS
Expr returns the following exit codes:
0 if the expression is neither null nor `0',
1 if the expression is null or `0',
2 for invalid expressions.
EXPR(1)