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
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)
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)
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,
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|"$0"\n"}' file1.txt
This is checking for only integers ( without... (10 Replies)
I have a txt file as database. when i run my program what it does is it ask me for 3 name and stored in the file as
name1:name2:name3:1
when u enter 3 name it add those in file as above format and add 1 at the end. I what i want is if i enter same names again it changes that 1 to 2 and so... (3 Replies)
Hey I'm new in linux,
I'm looking for a code to check whether the parameter is a number or a string.
I have already tried this code:
eerste=$(echo $1 | grep "^*$">aux)
if
But it doesn't work.:confused:
Thanks (2 Replies)
I 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)
I have below code inside my awk script
if ( $0 ~ /SVC IN:/ )
{
svc_in=substr( $0,23 , 3);
if (msg_start == 1 && msg_end == 0)
{
msg_arr=$0;
}
}
else if ( $0 ~ /^SVC OUT:/ )
{
svc_out=substr( $0, 9, 3);
if (msg_start == 1 && msg_end == 0)
... (6 Replies)
Discussion started by: bhagya123
6 Replies
LEARN ABOUT XFREE86
regex
regex(1F) FMLI Commands regex(1F)NAME
regex - match patterns against a string
SYNOPSIS
regex [-e] [ -v "string"] [ pattern template] ... pattern [template]
DESCRIPTION
The regex command takes a string from the standard input, and a list of pattern / template pairs, and runs regex() to compare the string
against each pattern until there is a match. When a match occurs, regex writes the corresponding template to the standard output and
returns TRUE. The last (or only) pattern does not need a template. If that is the pattern that matches the string, the function simply
returns TRUE. If no match is found, regex returns FALSE.
The argument pattern is a regular expression of the form described in regex(). In most cases, pattern should be enclosed in single quotes
to turn off special meanings of characters. Note that only the final pattern in the list may lack a template.
The argument template may contain the strings $m0 through $m9, which will be expanded to the part of pattern enclosed in ( ... )$0 through
( ... )$9 constructs (see examples below). Note that if you use this feature, you must be sure to enclose template in single quotes so
that FMLI does not expand $m0 through $m9 at parse time. This feature gives regex much of the power of cut(1), paste(1), and grep(1), and
some of the capabilities of sed(1). If there is no template, the default is $m0$m1$m2$m3$m4$m5$m6$m7$m8$m9.
OPTIONS
The following options are supported:
-e Evaluates the corresponding template and writes the result to the standard output.
-v "string" Uses string instead of the standard input to match against patterns.
EXAMPLES
Example 1: Cutting letters out of a string
To cut the 4th through 8th letters out of a string (this example will output strin and return TRUE):
`regex -v "my string is nice" '^.{3}(.{5})$0' '$m0'`
Example 2: Validating input in a form
In a form, to validate input to field 5 as an integer:
valid=`regex -v "$F5" '^[0-9]+$'`
Example 3: Translating an environment variable in a form
In a form, to translate an environment variable which contains one of the numbers 1, 2, 3, 4, 5 to the letters a, b, c, d, e:
value=`regex -v "$VAR1" 1 a 2 b 3 c 4 d 5 e '.*' 'Error'`
Note the use of the pattern '.*' to mean "anything else".
Example 4: Using backquoted expressions
In the example below, all three lines constitute a single backquoted expression. This expression, by itself, could be put in a menu defini-
tion file. Since backquoted expressions are expanded as they are parsed, and output from a backquoted expression (the cat command, in this
example) becomes part of the definition file being parsed, this expression would read /etc/passwd and make a dynamic menu of all the login
ids on the system.
`cat /etc/passwd | regex '^([^:]*)$0.*$' '
name=$m0
action=`message "$m0 is a user"`'`
DIAGNOSTICS
If none of the patterns match, regex returns FALSE, otherwise TRUE.
NOTES
Patterns and templates must often be enclosed in single quotes to turn off the special meanings of characters. Especially if you use the
$m0 through $m9 variables in the template, since FMLI will expand the variables (usually to "") before regex even sees them.
Single characters in character classes (inside []) must be listed before character ranges, otherwise they will not be recognized. For exam-
ple, [a-zA-Z_/] will not find underscores (_) or slashes (/), but [_/a-zA-Z] will.
The regular expressions accepted by regcmp differ slightly from other utilities (that is, sed, grep, awk, ed, and so forth).
regex with the -e option forces subsequent commands to be ignored. In other words, if a backquoted statement appears as follows:
`regex -e ...; command1; command2`
command1 and command2 would never be executed. However, dividing the expression into two:
`regex -e ...``command1; command2`
would yield the desired result.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO awk(1), cut(1), grep(1), paste(1), sed(1), regcmp(3C), attributes(5)SunOS 5.10 12 Jul 1999 regex(1F)