The problem can easily be solved by considering what a "number" is actually and since this is a good opportunity to show how to develop regular expressions I will explain that in greater detail:
1st Try
The only characters allowed should be 0-9. This covers for "123", but not for "123.0". Hence
2nd Try
Only 0-9 are allowed, save for exactly 1 character, which may be a fullstop. This definition covers "123" and "456.78", leaves out (quite correctly) "123.456.789", but doesn't cover "-123.0" or "+123.0". Hence
3rd Try
In addition to 2nd Try the first character may be "+" or "-" optionally. This covers every number and leaves out any non-number, so this solution is perfect.
We develop a simple sed-statement from there, by consecutively throwing out all "allowed" chars and look, if something remains. If something remains it is non-numeric, if not, then it is numeric:
Here is the sed-statement in detail:
s/^[+-]// - see 3rd try, we chop off leading +/- signs
s/[0-9]//g - see 1st try, we throw out all numerical digits
s/\.// - see 2nd try, we throw out one possible decimal point
I want to append file with a string but before doing that i want to check if this string already exist in that file.I tried with grep on Solaris 10 but unsuccessful.Man pages from grep seems to suggest if the string is found command status will be 0 and if not 1.But i am not finding it.May be i... (2 Replies)
Hey I'm new in linux,
I'm looking for a code to check whether the parameter is a number or a string.
I have already tried this code:
eerste=$(echo $1 | grep "^*$">aux)
if
But it doesn't work.:confused:
Thanks (2 Replies)
I have a txt file as database. when i run my program what it does is it ask me for 3 name and stored in the file as
name1:name2:name3:1
when u enter 3 name it add those in file as above format and add 1 at the end. I what i want is if i enter same names again it changes that 1 to 2 and so... (3 Replies)
Hi,
I have a file with data as given
$cat file1.txt
123
234
23e
234.456
234.876e
345.00
I am checking if the values are proper integers using the command.
nawk -F'|' 'int($1)!=$1 {printf "Error in field 1|"$0"\n"}' file1.txt
This is checking for only integers ( without... (10 Replies)
Hi,
Can anyone help me out to check whether the input argument is number?
Example:
REQUEST_ID="123456"
I need to check the REQUEST_ID value is number or string.
Thanks in Advance
Regards
BS (6 Replies)
Hi,
Can anyone help in the below problem.
file1 has the below contents
fileset 999 primary-ilist inode 37020 has invalid dotdot (426094) -> Not exist
fileset 999 primary-ilist inode 115016 dup block ->... (9 Replies)
Hello All,
Plz help me with:
I have a csv file with data separated by ',' and optionally enclosed by "". I want to check each of these values to see if they exceed the specified string length, and if they do I want to cut just that value to the max length allowed and keep the csv format as it... (9 Replies)