I am trying to write a regex expression to use it in C#
The use of the regex is to get a substring of the input according to the input size
The regex expression target
If the input size less than 13 then get the full input
Else if the input size is greater than 25 then get from the input the substring from index 3 till index 16 (so that I skip the first three chars)
Here is what I came with till now
(?(?=.{25,}).{3}(.{13})|(?(?=.{0,13})(.{0,13})))
This is not working since when the input size is greater than 25 the result is not trimming the first three chars
Check it here
Note that a non-regex solution is rather trivial:
public string check(string s)
{
var res = "";
if (s.Length>=25)
res = s.Substring(3,13);
else if (s.Length <= 13)
res = s;
return res;
}
If you want to use a regex, you may use
^(?=.{25,}).{3}(?<res>.{13})|^(?=.{0,13}$)(?<res>.*)
See the regex demo. Compile with RegexOptions.Singleline to support newlines in the input.
Details
^ - start of string
(?=.{25,}) - if there are 25 or more chars after the start of string, match
.{3} - any 3 chars
(?<res>.{13}) - and capture 13 chars into res group
| - or
^(?=.{0,13}$) - make sure there are no more than 0 to 13 chars in the string and then
(?<res>.*) - grab the whole string (if no RegexOptions.Singleline is used, only 1 line will be matched).
Use it as
var res = "";
var m = Regex.Match(s, #"^(?=.{25,}).{3}(?<res>.{13})|^(?=.{0,13}$)(?<res>.*)")
if (m.Success)
{
res = m.Groups["res"].Value;
}
See a C# demo.
I need a regex to match this pattern ( using C# )
My match must start with 2 alpha characters ( MA or CA ) and must end with either 6 or seven numeric digits; such as CA123456 or MA123456 or MA1234567
Here is what I tried:
Regex.IsMatch(StringInput, #"^[MA]{2}|^[CA]{2}\d{6,7}?"))
Unfortunately, it seems to match most anything
Try this pattern:
^[MC]A\d{6,7}$
The leading character class ([MC]) requires either an M or a C at the start of the string. Afterwards, \d{6,7} matches either 6 or 7 digits.
The issue with your pattern is the first alternative: ^[MA]{2} matches any string that starts with AA, AM, MA, or MM. It doesn't require any following digits at all. Since the regex engine can match the first alternative for a string like AA1234567 (matching the substring AA), it doesn't even attempt to find another match. This is why
it seems to match most anything.
I believe there are great usages of RegEx; in this particular case, using the built-in string functions of C# may be a better option:
Must start with either MA or CA
Must end with at least 6 digits (if there are 7, then there will be 6 digits)
Combining 1 and 2, the string must be at least 8 characters long
This would be the string version based on the above rules:
public static bool IsValid( string str )
{
if( str.Length < 8 )
{
return false;
}
if( !str.StartsWith( "CA" ) && !str.StartsWith( "MA" ) )
{
return false;
}
int result;
string end = str.Substring( str.Length - 6 );
bool isValid = int.TryParse( end, out result );
return isValid;
}
I am trying to find a regex which will give me the following validation:
string should contain at least 1 digit and at least 1 special character. Does allow alphanumeric.
I tried the following but this fails:
#"^[a-zA-Z0-9##$%&*+\-_(),+':;?.,!\[\]\s\\/]+$]"
I tried "password1$" but that failed
I also tried "Password1!" but that also failed.
ideas?
UPDATE
Need the solution to work with C# - currently the suggestions posted as of Oct 22 2013 do not appear to work.
Try this:
Regex rxPassword = new Regex( #"
^ # start-of-line, followed by
[a-zA-Z0-9!##]+ # a sequence of one or more characters drawn from the set consisting of ASCII letters, digits or the punctuation characters ! # and #
(<=[0-9]) # at least one of which is a decimal digit
(<=[!##]) # at least one of which is one of the special characters
(<=[a-zA-Z]) # at least one of which is an upper- or lower-case letter
$ # followed by end-of-line
" , RegexOptions.IgnorePatternWhitespace ) ;
The construct (<=regular-expression) is a zero-width positive look-behind assertion.
Sometimes it's a lot simpler to do things one step at a time. The static constructor builds the escaped character class characters from a simple list of allowed special characters. The built-in Regex.Escape method doesn't work here.
public static class PasswordValidator {
private const string ALLOWED_SPECIAL_CHARS = #"##$%&*+_()':;?.,![]\-";
private static string ESCAPED_SPECIAL_CHARS;
static PasswordValidator() {
var escapedChars = new List<char>();
foreach (char c in ALLOWED_SPECIAL_CHARS) {
if (c == '[' || c == ']' || c == '\\' || c == '-')
escapedChars.AddRange(new[] { '\\', c });
else
escapedChars.Add(c);
}
ESCAPED_SPECIAL_CHARS = new string(escapedChars.ToArray());
}
public static bool IsValidPassword(string input) {
// Length requirement?
if (input.Length < 8) return false;
// First just check for a digit
if (!Regex.IsMatch(input, #"\d")) return false;
// Then check for special character
if (!Regex.IsMatch(input, "[" + ESCAPED_SPECIAL_CHARS + "]")) return false;
// Require a letter?
if (!Regex.IsMatch(input, "[a-zA-Z]")) return false;
// DON'T allow anything else:
if (Regex.IsMatch(input, #"[^a-zA-Z\d" + ESCAPED_SPECIAL_CHARS + "]")) return false;
return true;
}
}
This may be work, there are two possible, the digit before special char or the digit after the special char. You should use DOTALL(the dot point all char)
^((.*?[0-9].*?[##$%&*+\-_(),+':;?.,!\[\]\s\\/].*)|(.*?[##$%&*+\-_(),+':;?.,!\[\]\s\\/].*?[0-9].*))$
This worked for me:
#"(?=^[!##$%\^&*()_-+=[{]};:<>|./?a-zA-Z\d]{8,}$)(?=([!##$%\^&*()_-+=[{]};:<>|./?a-zA-Z\d]\W+){1,})(?=[^0-9][0-9])[!##$%\^&*()_-+=[{]};:<>|./?a-zA-Z\d]*$"
alphanumeric, at least 1 numeric, and special character with a min length of 8
This should do the work
(?:(?=.*[0-9]+)(?=.*[a-zA-Z]+)(?=.*[##$%&*+\-_(),+':;?.,!\[\]\s\\/]+))+
Tested with javascript, not sure about c#, may need some little adjust.
What it does is use anticipated positive lookahead to find the required elements of the password.
EDIT
Regular expression is designed to test if there are matches. Since all the patterns are lookahead, no real characters get captured and matches are empty, but if the expression "match", then the password is valid.
But, since the question is C# (sorry, i don't know c#, just improvising and adapting samples)
string input = "password1!";
string pattern = #"^(?:(?=.*[0-9]+)(?=.*[a-zA-Z]+)(?=.*[##$%&*+\-_(),+':;?.,!\[\]\s\\/]+))+.*$";
Regex rgx = new Regex(pattern, RegexOptions.None);
MatchCollection matches = rgx.Matches(input);
if (matches.Count > 0) {
Console.WriteLine("{0} ({1} matches):", input, matches.Count);
foreach (Match match in matches)
Console.WriteLine(" " + match.Value);
}
Adding start of line, and a .*$ to the end, the expression will match if the password is valid. And the match value will be the password. (i guess)
I have this string in C#
adj_con(CL2,1,3,0),adj_cont(CL1,1,3,0),NG, NG/CL, 5 value of CL(JK), HO
I want to use a RegEx to parse it to get the following:
adj_con(CL2,1,3,0)
adj_cont(CL1,1,3,0)
NG
NG/CL
5 value of CL(JK)
HO
In addition to the above example, I tested with the following, but am still unable to parse it correctly.
"%exc.uns: 8 hours let # = ABC, DEF", "exc_it = 1 day" , " summ=graffe ", " a,b,(c,d)"
The new text will be in one string
string mystr = #"""%exc.uns: 8 hours let # = ABC, DEF"", ""exc_it = 1 day"" , "" summ=graffe "", "" a,b,(c,d)""";
string str = "adj_con(CL2,1,3,0),adj_cont(CL1,1,3,0),NG, NG/CL, 5 value of CL(JK), HO";
var resultStrings = new List<string>();
int? firstIndex = null;
int scopeLevel = 0;
for (int i = 0; i < str.Length; i++)
{
if (str[i] == ',' && scopeLevel == 0)
{
resultStrings.Add(str.Substring(firstIndex.GetValueOrDefault(), i - firstIndex.GetValueOrDefault()));
firstIndex = i + 1;
}
else if (str[i] == '(') scopeLevel++;
else if (str[i] == ')') scopeLevel--;
}
resultStrings.Add(str.Substring(firstIndex.GetValueOrDefault()));
Event faster:
([^,]*\x28[^\x29]*\x29|[^,]+)
That should do the trick. Basically, look for either a "function thumbprint" or anything without a comma.
adj_con(CL2,1,3,0),adj_cont(CL1,1,3,0),NG, NG/CL, 5 value of CL(JK), HO
^ ^ ^ ^ ^
The Carets symbolize where the grouping stops.
Just this regex:
[^,()]+(\([^()]*\))?
A test example:
var s= "adj_con(CL2,1,3,0),adj_cont(CL1,1,3,0),NG, NG/CL, 5 value of CL(JK), HO";
Regex regex = new Regex(#"[^,()]+(\([^()]*\))?");
var matches = regex.Matches(s)
.Cast<Match>()
.Select(m => m.Value);
returns
adj_con(CL2,1,3,0)
adj_cont(CL1,1,3,0)
NG
NG/CL
5 value of CL(JK)
HO
If you simply must use Regex, then you can split the string on the following:
, # match a comma
(?= # that is followed by
(?: # either
[^\(\)]* # no parens at all
| # or
(?: #
[^\(\)]* # ...
\( # (
[^\(\)]* # stuff in parens
\) # )
[^\(\)]* # ...
)+ # any number of times
)$ # until the end of the string
)
It breaks your input into the following:
adj_con(CL2,1,3,0)
adj_cont(CL1,1,3,0)
NG
NG/CL
5 value of CL(JK)
HO
You can also use .NET's balanced grouping constructs to create a version that works with nested parens, but you're probably just as well off with one of the non-Regex solutions.
Another way to implement what Snowbear was doing:
public static string[] SplitNest(this string s, char src, string nest, string trg)
{
int scope = 0;
if (trg == null || nest == null) return null;
if (trg.Length == 0 || nest.Length < 2) return null;
if (trg.IndexOf(src) >= 0) return null;
if (nest.IndexOf(src) >= 0) return null;
for (int i = 0; i < s.Length; i++)
{
if (s[i] == src && scope == 0)
{
s = s.Remove(i, 1).Insert(i, trg);
}
else if (s[i] == nest[0]) scope++;
else if (s[i] == nest[1]) scope--;
}
return s.Split(trg);
}
The idea is to replace any non-nested delimiter with another delimiter that you can then use with an ordinary string.Split(). You can also choose what type of bracket to use - (), <>, [], or even something weird like \/, ][, or `'. For your purposes you would use
string str = "adj_con(CL2,1,3,0),adj_cont(CL1,1,3,0),NG, NG/CL, 5 value of CL(JK), HO";
string[] result = str.SplitNest(',',"()","~");
The function would first turn your string into
adj_con(CL2,1,3,0)~adj_cont(CL1,1,3,0)~NG~ NG/CL~ 5 value of CL(JK)~ HO
then split on the ~, ignoring the nested commas.
Assuming non nested, matching parentheses, you can easily match the tokens you want instead of splitting the string:
MatchCollection matches = Regex.Matches(data, #"(?:[^(),]|\([^)]*\))+");
var s = "adj_con(CL2,1,3,0),adj_cont(CL1,1,3,0),NG, NG/CL, 5 value of CL(JK), HO";
var result = string.Join(#"\n",Regex.Split(s, #"(?<=\)),|,\s"));
The pattern matches for ) and excludes it from the match then matches ,
or
matches , followed by a space.
result =
adj_con(CL2,1,3,0)
adj_cont(CL1,1,3,0)
NG
NG/CL
5 value of CL(JK)
HO
The TextFieldParser (msdn) class seems to have the functionality built-in:
TextFieldParser Class: - Provides methods and properties for parsing structured text files.
Parsing a text file with the TextFieldParser is similar to iterating over a text file, while the ReadFields method to extract fields of text is similar to splitting the strings.
The TextFieldParser can parse two types of files: delimited or fixed-width. Some properties, such as Delimiters and HasFieldsEnclosedInQuotes are meaningful only when working with delimited files, while the FieldWidths property is meaningful only when working with fixed-width files.
See the article which helped me find that
Here's a stronger option, which parses the whole text, including nested parentheses:
string pattern = #"
\A
(?>
(?<Token>
(?:
[^,()] # Regular character
|
(?<Paren> \( ) # Opening paren - push to stack
|
(?<-Paren> \) ) # Closing paren - pop
|
(?(Paren),) # If inside parentheses, match comma.
)*?
)
(?(Paren)(?!)) # If we are not inside parentheses,
(?:,|\Z) # match a comma or the end
)*? # lazy just to avoid an extra empty match at the end,
# though it removes a last empty token.
\Z
";
Match match = Regex.Match(data, pattern, RegexOptions.IgnorePatternWhitespace);
You can get all matches by iterating over match.Groups["Token"].Captures.
I got the following :
01.05.03
I need to convert that to 1.5.3
The problem is I cannot only trim the 0 because if I got :
01.05.10
I need to convert that to 1.5.10
So, what's the better way to solve that problem ? Regex ? If so, any regex example doing that ?
Expanding on the answer of #FrustratedWithFormsDesigner:
string Strip0s(string s)
{
return string.Join<int>(".", from x in s.Split('.') select int.Parse(x));
}
Regex-replace
(?<=^|\.)0+
with the empty string. The regex is:
(?<= # begin positive look-behind (i.e. "a position preceded by")
^|\. # the start of the string or a literal dot †
) # end positive look-behind
0+ # one or more "0" characters
† note that not all regex flavors support variable-length look-behind, but .NET does.
If you expect this kind of input: "00.03.03" and want to to keep the leading zero in this case (like "0.3.3"), use this expression instead:
(?<=^|\.)0+(?=\d)
and again replace with the empty string.
From the comments (thanks Kobi): There is a more concise expression that does not require look-behind and is equivalent to my second suggestion:
\b0+(?=\d)
which is
\b # a word boundary (a position between a word char and a non-word char)
0+ # one or more "0" characters
(?=\d) # positive look-ahead: a position that's followed by a digit
This works because the 0 happens to be a word character, so word boundaries can be used to find the first 0 in a row. It is a more compatible expression, because many regex flavors do not support variable-length look-behind, and some (like JavaScript) no look-behind at all.
You could split the string on ., then trim the leading 0s on the results of the split, then merge them back together.
I don't know of a way to do this in a single operation, but you could write a function that hides this and makes it look like a single operation. ;)
UPDATE:
I didn't even think of the other guy's regex. Yeah, that will probably do it in a single operation.
Here's another way you could do what FrustratedWithFormsDesigner suggests:
string s = "01.05.10";
string s2 = string.Join(
".",
s.Split('.')
.Select(str => str.TrimStart('0'))
.ToArray()
);
This is almost the same as dtb's answer, but doesn't require that the substrings be valid integers (it would also work with, e.g., "000A.007.0HHIMARK").
UPDATE: If you'd want any strings consisting of all 0s in the input string to be output as a single 0, you could use this:
string s2 = string.Join(
".",
s.Split('.')
.Select(str => TrimLeadingZeros(str))
.ToArray()
);
public static string TrimLeadingZeros(string text) {
int number;
if (int.TryParse(text, out number))
return number.ToString();
else
return text.TrimStart('0');
}
Example input/output:
00.00.000A.007.0HHIMARK // input
0.0.A.7.HHIMARK // output
There's also the old-school way which probably has better performance characteristics than most other solutions mentioned. Something like:
static public string NormalizeVersionString(string versionString)
{
if(versionString == null)
throw new NullArgumentException("versionString");
bool insideNumber = false;
StringBuilder sb = new StringBuilder(versionString.Length);
foreach(char c in versionString)
{
if(c == '.')
{
sb.Append('.');
insideNumber = false;
}
else if(c >= '1' && c <= '9')
{
sb.Append(c);
insideNumber = true;
}
else if(c == '0')
{
if(insideNumber)
sb.Append('0');
}
}
return sb.ToString();
}
string s = "01.05.10";
string newS = s.Replace(".0", ".");
newS = newS.StartsWith("0") ? newS.Substring(1, newS.Length - 1) : newS;
Console.WriteLine(newS);
NOTE: You will have to thoroughly check for possible input combination.
This looks like it is a date format, if so I would use Date processing code
DateTime time = DateTime.Parse("01.02.03");
String newFormat = time.ToString("d.M.yy");
or even better
String newFormat = time.ToShortDateString();
which will respect you and your clients culture setting.
If this data is not a date then don't use this :)
I had a similar requirement to parse a string with street adresses, where some of the house numbers had leading zeroes and I needed to remove them while keeping the rest of the text intact, so I slightly edited the accepted answer to meet my requirements, maybe someone finds it useful. Basically doing the same as accepted answer, with the difference that I am checking if the string part can be parsed as an integer, and defaulting to the string value when false;
string Strip0s(string s)
{
int outputValue;
return
string.Join(" ",
from x in s.Split(new[] { ' ' })
select int.TryParse(x, out outputValue) ? outputValue.ToString() : x);
}
Input: "Islands Brygge 34 B 07 TV"
Output: "Islands Brygge 34 B 7 TV"