In AIX (including 5.3) /bin/ksh is a ksh88, whereas /bin/ksh93 is a ksh93. The substr()-function in the form "${var:start:length}" is only implemented in ksh93.
cfajohnsons observation is correct in a very general way: using ksh93-functions always runs the risk of getting less portable. On the other hand: using an external tool (expr, sed, awk, whatever) to trim the variables content is expensive in terms of system calls. I would like to offer the following solution to this problem, which which work in every ksh.version:
The first line extracts the first 5 characters from the string $DDNAME, the second statement extracts the last 2 from these 5 characters, effectively giving the substring starting at pos 4, length 2. Because this is done completely in the shell and without calling an external program it shoulld be by far faster than any solution based on such a program.
cfajohnson already explained how this can be tested for being an integer or not.
Hi,
I am new stuff to learn substr() function through awk for writing the Korn shell script.
Is there a way to copy from XXXX1234.ABCDEF to XXX1234 file names without changing both data files?
I appreciate your time to response this email.
Thanks,
Steve (4 Replies)
What is the difference between test expr VS .
For example :
if test 5 -eq 6
echo "Wrong"
and
if
echo "Wrong"
bot will give the same output as Wrong.
Now, what is the difference between these two? though they are producing the same result why we need two?
Any answer will be... (2 Replies)
hi
iam trying to extract a certain portion of the string whose value is stored below,but am getting syntax eror.The command is shown below
for file in GMG_BASEL2*.txt
do
m1= cat reporting_date.txt
year= expr substr $m1 1 2
echo $year
done
m1 has date 10/31/2009
but this vale... (6 Replies)
Hi all,
i am facing the error "expr: non-numeric argument" when i use the expr command.
Following is the expression which i want to execute
HR=$(echo `date +%H`)
MIN=$(echo `date +%M`)
TOT_MIN=`expr "$HR" \* 60+$MIN` | bc
echo $TOT_MIN
Here I am being reported with the error expr:... (6 Replies)
Can someone tell me how to change the first column in a very large 17k line file from a random 10 digit numeric value to a non numeric value. The format of lines in the file is:
1702938475,SNU022,201004
the first 10 numbers always begin with 170 (6 Replies)
Hi all,
I want to get each line of a data file from position 464 plus 8 characters. I tried in two different ways, and the results were different. I'd like to know why.
First method, using awk:
awk '{print substr($0,464,8)}' CONCIL_VUELTA_ALF_100112_0801.okSecond method, using scripting:... (5 Replies)
Hi All,
I'm writing a shell script in KSH, where I want to store the filename, total record count and actual record count of all the source files. The source files reside in 4 different sub-folders under the same root folder.
Below is code:
#!/usr/bin/ksh... (6 Replies)
Hi,
I tried to look up the issue i'm experiencing, but i'm confused what's wrong with my script.
After executing the script I'm getting the following error
expr: non-numeric argument
syntax error on line 1, teletype
After some research, it seems that the problem relates to bc.
I have... (1 Reply)
Discussion started by: nms
1 Replies
LEARN ABOUT ULTRIX
test
test(1) General Commands Manual test(1)Name
test - test conditional expression
Syntax
test expr
[ expr ]
Description
The command evaluates the expression expr. If the value of expr is true, the command returns a zero exit status; otherwise, it returns a
nonzero exit status. The command also returns a nonzero exit status if no arguments are specified.
Options
The following primitives are used to construct expr:
-r file Tests if the file exists and is readable.
-w file Tests if the file exists and is writable.
-f file Tests if the file exists and is not a directory.
-d file Tests if the file exists and is a directory.
-s file Tests if the file exists and has a size greater than zero.
-t [ fildes ] Tests if the open file, whose file descriptor number is fildes (1 by default), is associated with a terminal device.
-z s1 Tests if the length of string s1 is zero.
-n s1 Tests if the length of the string s1 is nonzero.
s1 = s2 Tests if the strings s1 and s2 are equal.
s1 != s2 Tests if the strings s1 and s2 are not equal.
s1 Tests if s1 is not the null string.
n1 -eq n2 Tests if number1 equals number2.
n1 -ge n2 Tests if number1 is greater than or equal to number2.
n1 -gt n2 Tests if number1 is greater than number2.
n1 -le n2 Tests if number1 is less than or equal to number2.
n1 -lt n2 Tests if number1 is less than number2.
n1 -ne n2 Tests if number1 is not equal to number2.
These primitives can be combined with the following operators:
!expr Negates evaluation of expression.
expr -a expr Tests logical and of two expressions.
expr -o expr Tests logical or of two expressions.
( expr... ) Groups expressions.
The -a operator takes precedence over the -o operator. Note that all the operators and flags are separate arguments to Note also that
parentheses are meaningful to the Shell and must be escaped.
See Alsofind(1), sh(1), test(1sh5)test(1)