06-14-2005
Quote:
Originally Posted by yongho
Question: I just started learning shell scripting a few days ago and I was under the assumption that you didn't need to typeset anything.
you don't.
if you
don't,
count=$((count + 1))
becomes
count=$((
$count + 1))
Quote:
Originally Posted by yongho
One of my previous counters looked like this (in a while statement, not an if statement:
var1=`expr $var1 + $var2`
..and it worked.
this
NOT using ksh/bash
builtin capabilities for doing simple integer math.
Quote:
Originally Posted by yongho
But when I tried the expr command in the if statement, it didn't increment at all. Would you know why this is? Could it be because once you enter an if statement, you must use different rules?
nope, that's not it.
are you saying that the 'expr ' increment
did not work, but the 'count=$((count+1))'
did?
there must be something else different in your 'while' loop.
is your 'while' loopbeing
piped with data?
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi All,
Can some one tell me how to get run the following:
data1="hello"
data2="world"
if
then
{
echo "good afternnon"
}
else
{
echo " good morning"
}
fi
The above code gives me an error ad below :
./if.h: line 3: ' (7 Replies)
Discussion started by: jisha
7 Replies
2. Shell Programming and Scripting
VARIABLE="project"
if && ]
then
echo "VARIABLE is not empty"
fi
this is not working what is wrong in the syntax?? (2 Replies)
Discussion started by: codeman007
2 Replies
3. Shell Programming and Scripting
Hi, I hope the title does not scare people to look into this thread but it describes roughly what I'm trying to do. I need a solution in PHP.
I'm a programming beginner, so it might be that the approach to solve this, might be easier to solve with an other approach of someone else, so if you... (0 Replies)
Discussion started by: lowmaster
0 Replies
4. Programming
Hello there,
My first time on the forums, glad to be here :)
I'm completely new to programming in PHP and I have a question which I hope someone could help me with.
I am currently using this statement:
if(($session == 2) && ($item == Dagger) && ($item2 == Dagger)){
... (5 Replies)
Discussion started by: Hero
5 Replies
5. Shell Programming and Scripting
Hi
What is the syntax for if statement using && and || operator?
if && ] ||
here its giving me an error to this if statement
any suggestion?? (2 Replies)
Discussion started by: Avi
2 Replies
6. Shell Programming and Scripting
Hi, I'm using the && operator in if statement:
if ; then
exp $UID/$PWD@$ORACLE_SID FILE=./DUMP/$TODAY$CONCAT_STR$USERNAME.dmp STATISTICS=NONE LOG=./LOG/$TODAY$CONCAT_STR$USERNAME.log
elif ; then
expdp $UID/$PWD@$ORACLE_SID DIRECTORY=./DUMP/ DUMPFILE=$TODAY$CONCAT_STR$USERNAME.dmp... (8 Replies)
Discussion started by: priya001
8 Replies
7. Shell Programming and Scripting
how do you write an if statement for something like
if ((expr 1 >= expr 2 && expr 3 >= expr 4) && expr 5 <= expr 6)
if ((TRUE && TRUE) && TRUE) then
condition...
i've done it this way but it doesn't seem to work.
if (] && "$ex_day" -le "$curr_day" ); then
condition... (3 Replies)
Discussion started by: angilulu
3 Replies
8. Shell Programming and Scripting
Firstly, I would like to apologize if this is not the appropriate sub-forum to post about GNU/BSD makefile scripting. Though my code is in C++, because I am focusing on the makefile I thought it would go better in shell scripting. Please correct me if I am wrong.
Secondly, I am not interested in... (0 Replies)
Discussion started by: AntumDeluge
0 Replies
9. Shell Programming and Scripting
Hi All,
Do you have any sample script,
- auto get file from SFTP remote server and delete file in remove server after downloaded.
- only download specify filename
- auto upload file from local to SFTP remote server and delete local folder file after uploaded
- only upload specify filename
... (3 Replies)
Discussion started by: weesiong
3 Replies
10. Shell Programming and Scripting
Hello,
Below I try to control that the input is good an IP :
#!/bin/bash
cp /home/scripts/choice_interfaces.txt /home/scripts/interfaces.txt
chmod 644 /home/scripts/interfaces.txt
echo -e "Please enter the network informations into the /etc/network/interfaces file, complete them below... (9 Replies)
Discussion started by: Arnaudh78
9 Replies
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)