On assignments to a variable, do x= instead of $x= .
When you use a mixture of -o and -a, you might have to control precedence. In the following, the first line would test true because -o has precedence:
if [ a = a -o b = b -a c = C ]
But add parentheses (you would need to backslash these) and it would now test false:
if [ ( a = a -o b = b ) -a c = C ]
Also, when checking for several values, a case statement makes for nice clean code, and even more handy when each value will result in a different action:
I want to do multiple comparisons on a series of numbers from an array:
I send the numbers in file1 through want to print out some info from file2 based on some conditions.
The syntax just isn't correct???
awk '
NR==FNR{
a=$0
next
... (2 Replies)
Is it possible to setup two conditions for an if then statement in a pbash script?
For example, depending on the text value of a variable I parse out of an xml file, I want to assign it a numerical values.
Example:
if ; then
VAR="25"
fi
if ; then
VAR="25"
fi
Can these two... (3 Replies)
Hi All,
I am new to shell scripting.
Can any one say what is wrong in this if statement, that uses multiple conditions
if
then
***************
else
if ( -z $pcs && "$night_time_calc" > "$night_time" )
then
********************************
... (4 Replies)
Please help me. I have been doing this for several hours.
Here is the code
if then
echo a b c d >> file.txt
echo 1111 >> file.txt
fi
The reason I want the two echo is because I want these statements printed on multiple lines. I keep getting error .
First it tells me... (2 Replies)
Hi,
Hav automated a process, and it is working fine.
for first process alone
status = ` ps -ef |grep a `
if
then
echo " Success" > temp/logfile
else
echo " Failure" > temp/logfile
fi
Now I hav to write script to automated some 2 process and then send mail using cron..
... (5 Replies)
how can we execute multiple statements in
else condition
i have
if
then
statement
else
statements
fi
in else condition i have multiple statements
but it executing only one statement
is there any way to execute multiple statements (4 Replies)
Hi All,
I need to check for 3 conditions and if all the 3 are not satified need to say that services are not running....
is the below code correct.
#********** Check to see if Service 1 is still running**************
if
then
echo "$datetimestamp: Service1 is not running" >>... (4 Replies)
I'm working on a script for class as a final project. We have to ask for values (city, state, zip) five times, but the state can only be MI, IN, IL, or OH. I'm trying to do this with a while loop inside of a while loop, but I have no idea how to do it properly.
Here's what I have so far:
... (3 Replies)
exmaple:
file1 and file2 has 1 bit
if
then
exit
else
send out email
fi
if
then
exit
else
send out email
fi
it exits the 1st if. did not continue with my 2nd if. thanks in advanced.
Please use CODE tags are suggested on every page when you post an item in... (7 Replies)
Hello,
I am new to scripting and I am trying to write a simple script that creates users and adds their passwords from two files; one a user list file and another a password list file.
For example, I have two files already.
$ cat file1
andy
stephane
aby
paul
$ cat file2
123
234... (4 Replies)
Discussion started by: FemoTheDon
4 Replies
LEARN ABOUT BSD
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 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.
7th Edition April 29, 1985 EXPR(1)