I have the necessity to use this command:
cat file1 | grep $A | grep $B
where sometime A and, or, B are not set.
For example:
I set A=@
never defined or set B
The above command send a cat error.
Any idea?
Thanks.
Giovanni (1 Reply)
hi forum
i beginning with script and i want test un null variable in a schell
i just don t know the syntax here is a litle example
y=test
echo $y
unset y
echo $y (so here Y = Null)
if Y=Null
then
echo "y is null"
exit
fi (1 Reply)
Hi,
I have to check whether an argument say $ARGV is not null in an if operator. Please let me know the operator. It would be great if you write a psuedo code.
Thanks in advance
Ammu (4 Replies)
korn shell
If
then
update_smartcare_user_password "$u_id"
else
echo "Not a database user"
fi
i get this error
Syntax error at line *** : `then' is not expected.
what should i do.
I want to check whether $a is null or not. (2 Replies)
Hi all, I have a stupid question on NULL and zero(0).
In a script I've been working with, one of the lines is:
if &&
then
The problem I seem to have is when $Current_csm2 is null, this if block is not triggered, and I don't get why because I was under the impression that NULL!=0
Can... (7 Replies)
Hello, Unix-forums!
My problem:
read -p "Enter any number, please" number
sleep 1
echo $number | tr -d 0-9
test -z $number && echo "Thank you" || echo "This is not a number"Test always displays "This is not a number". It doesn't matter if I entered a or 1.
But if I order
echo... (2 Replies)
i have this code
for i in `cat sql_output.txt`
do
-- some script commands
done
sql_output.txt has 1 column with employee_ids
If the sql_output.txt is null then the do loop should not execute.
How can i implement this.
for i in `cat sql_output.txt`
If i is null or empty
then ... (5 Replies)
Guys,
Please help me on the below
sample.cfg
var=NULL
sample.sh
#!/bin/sh
. /sample.cfg
if ;then
1 st command here
else
2 nd command here
fi (3 Replies)
DELETE=`cat $logfile1 | egrep -i "Delete" | sed 's/ */ /g' | cut -d" " -f2`
INSERT=`cat $logfile1 | egrep -i "Insert" | sed 's/ */ /g' | cut -d" " -f2`
UPDATE=`cat $logfile1 | egrep -i "Update" | sed 's/ */ /g' | cut -d" " -f2`
I need soming like below:
if value is null... (8 Replies)
Discussion started by: Veera_V
8 Replies
LEARN ABOUT MINIX
shift
shift(1) User Commands shift(1)NAME
shift - shell built-in function to traverse either a shell's argument list or a list of field-separated words
SYNOPSIS
sh
shift [n]
csh
shift [variable]
ksh
* shift [n]
DESCRIPTION
sh
The positional parameters from $n+1 ... are renamed $1 ... . If n is not given, it is assumed to be 1.
csh
The components of argv, or variable, if supplied, are shifted to the left, discarding the first component. It is an error for the variable
not to be set or to have a null value.
ksh
The positional parameters from $n+1 $n+1 ... are renamed $1 ..., default n is 1. The parameter n can be any arithmetic expression that
evaluates to a non-negative number less than or equal to $#.
On this man page, ksh(1) commands that are preceded by one or two * (asterisks) are treated specially in the following ways:
1. Variable assignment lists preceding the command remain in effect when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
4. Words, following a command preceded by ** that are in the format of a variable assignment, are expanded with the same rules as a vari-
able assignment. This means that tilde substitution is performed after the = sign and word splitting and file name generation are not
performed.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO csh(1), ksh(1), sh(1), attributes(5)SunOS 5.10 15 Apr 1994 shift(1)