You can just use the appropriate "test" option like:
From man page of "test"
Quote:
-s FILE
FILE exists and has a size greater than zero
If you need more precise things on regular expressions you could use grep, egrep or grep -E and check it's exit code ($?) or instead use awk or or ... whatever you want to do.
There are lots of other options that might come handy.
How to write this condition in ksh?
if myfile is empty or myfile does not exist
then
do action1
fi
is this OK?
if ] -o ] then
then
do action1
fi
Thanks. (3 Replies)
AIX 5.3 / KSH
I have a Java application which creates a log file a.log. I have a KSH script which does the following action
cp a.log /directory2/b.log
> a.log
After this the file size goes to 0 as per "ls -l"
Then next time when the application writes into this file, the file size... (4 Replies)
hi
how can I determine, if a file is empty or not?I am using read line clause.
The script should be like:
while read line
do
if(file is empty) then;
......
done < $blacklist (1 Reply)
Hi All,
I am checking for a empty input file to do some further action , but I am getting exit status 0 in both the cases , for empty and non empty file both.
The value of $? is coming 0 in if part also and else part too.
#!/bin/ksh
if ]; then
echo "data"
# exit 0
echo "$?"
else... (4 Replies)
This is the code:
while test 1 -eq 1
do
read a
$a
if test $a = stop
then
break
fi
done
I read a command on every loop an execute it.
I check if the string equals the word stop to end the loop,but it say that I gave too many arguments to test.
For example echo hello.
Now the... (1 Reply)
The below awk improved bu @MadeInGermany, works great as long as the input file has data in it in the below format:
input
chrX 25031028 25031925 chrX:25031028-25031925 ARX 631 18
chrX 25031028 25031925 chrX:25031028-25031925 ARX 632 14... (3 Replies)
Discussion started by: cmccabe
3 Replies
LEARN ABOUT REDHAT
while
while(n) Tcl Built-In Commands while(n)
__________________________________________________________________________________________________________________________________________________NAME
while - Execute script repeatedly as long as a condition is met
SYNOPSIS
while test body
_________________________________________________________________DESCRIPTION
The while command evaluates test as an expression (in the same way that expr evaluates its argument). The value of the expression must a
proper boolean value; if it is a true value then body is executed by passing it to the Tcl interpreter. Once body has been executed then
test is evaluated again, and the process repeats until eventually test evaluates to a false boolean value. Continue commands may be exe-
cuted inside body to terminate the current iteration of the loop, and break commands may be executed inside body to cause immediate termi-
nation of the while command. The while command always returns an empty string.
Note: test should almost always be enclosed in braces. If not, variable substitutions will be made before the while command starts execut-
ing, which means that variable changes made by the loop body will not be considered in the expression. This is likely to result in an
infinite loop. If test is enclosed in braces, variable substitutions are delayed until the expression is evaluated (before each loop iter-
ation), so changes in the variables will be visible. For an example, try the following script with and without the braces around $x<10:
set x 0
while {$x<10} {
puts "x is $x"
incr x
}
SEE ALSO
break(n), continue(n), for(n), foreach(n)
KEYWORDS
boolean value, loop, test, while
Tcl while(n)