Validating file types by regular expression

Question

I have a  NET webform that has a file upload control that is tied to a regular expression validator  This validator needs to validate that only certain filetypes should be allowed for upload  jpg gif doc pdf   The current regular expression that does this is         a-zA-Z        2  w           w  w       jpg  JPG  gif  GIF  doc  DOC  pdf  PDF      However this does not seem to be working    can anyone give me a little reg ex help

User · Answer

Are you just looking to verify that the file is of a given extension? You can simplify what you are trying to do with something like this:

(.*?)\.(jpg|gif|doc|pdf)$

Then, when you call IsMatch() make sure to pass RegexOptions.IgnoreCase as your second parameter. There is no reason to have to list out the variations for casing.

Edit: As Dario mentions, this is not going to work for the RegularExpressionValidator, as it does not support casing options.

User · Answer

Your regexp seems to validate both the file name and the extension  Is that what you need  I ll assume it s just the extension and would use a regexp like this      jpg gif doc pdf     And set the matching to be case insensitive

User · Answer

You can embed case insensitity into the regular expression like so       i     jpg gif doc pdf

User · Answer

dD  oO  cC  xX        pP  dD  fF       Will accept  doc   docx   pdf files having a filename of at least one character                 beginning of string               at least one character  any character                dot          pattern    match the pattern without storing the match   dD           any character in the set   d  or  D    xX           any character in the set or none                  x  may be missing so  doc  or  docx  are both accepted                either the previous or the next pattern               end of matched string   Warning  Without enclosing the whole chain of extensions in       an extension like  docpdf would pass   You can test regular expressions at http   www regextester com

User · Answer

You can embed case insensitity into the regular expression like so       i     jpg gif doc pdf

User · Answer

Are you just looking to verify that the file is of a given extension? You can simplify what you are trying to do with something like this:

(.*?)\.(jpg|gif|doc|pdf)$

Then, when you call IsMatch() make sure to pass RegexOptions.IgnoreCase as your second parameter. There is no reason to have to list out the variations for casing.

Edit: As Dario mentions, this is not going to work for the RegularExpressionValidator, as it does not support casing options.

User · Answer

Your regex seems a bit too complex in my opinion  Also  remember that the dot is a special character meaning  any character   The following regex should work  note the escaped dots          jpg JPG gif GIF doc DOC pdf PDF     You can use a tool like Expresso to test your regular expressions

User · Answer

Are you just looking to verify that the file is of a given extension? You can simplify what you are trying to do with something like this:

(.*?)\.(jpg|gif|doc|pdf)$

Then, when you call IsMatch() make sure to pass RegexOptions.IgnoreCase as your second parameter. There is no reason to have to list out the variations for casing.

Edit: As Dario mentions, this is not going to work for the RegularExpressionValidator, as it does not support casing options.

User · Answer

Your regexp seems to validate both the file name and the extension  Is that what you need  I ll assume it s just the extension and would use a regexp like this      jpg gif doc pdf     And set the matching to be case insensitive

User · Answer

You can embed case insensitity into the regular expression like so       i     jpg gif doc pdf

User · Answer

Your regex seems a bit too complex in my opinion  Also  remember that the dot is a special character meaning  any character   The following regex should work  note the escaped dots          jpg JPG gif GIF doc DOC pdf PDF     You can use a tool like Expresso to test your regular expressions

User · Answer

Your regex seems a bit too complex in my opinion  Also  remember that the dot is a special character meaning  any character   The following regex should work  note the escaped dots          jpg JPG gif GIF doc DOC pdf PDF     You can use a tool like Expresso to test your regular expressions

User · Answer

Your regexp seems to validate both the file name and the extension  Is that what you need  I ll assume it s just the extension and would use a regexp like this      jpg gif doc pdf     And set the matching to be case insensitive

User · Answer

You can embed case insensitity into the regular expression like so       i     jpg gif doc pdf

User · Answer

You can use this template for every file type   ValidationExpression          pP  dD  fF     jJ  pP  gG     pP  nN  gG         for ex  you can add   rR  aA  rR   for Rar file type and etc

User · Answer

Are you just looking to verify that the file is of a given extension? You can simplify what you are trying to do with something like this:

(.*?)\.(jpg|gif|doc|pdf)$

Then, when you call IsMatch() make sure to pass RegexOptions.IgnoreCase as your second parameter. There is no reason to have to list out the variations for casing.

Edit: As Dario mentions, this is not going to work for the RegularExpressionValidator, as it does not support casing options.

User · Answer

Your regexp seems to validate both the file name and the extension  Is that what you need  I ll assume it s just the extension and would use a regexp like this      jpg gif doc pdf     And set the matching to be case insensitive

User · Answer

Your regex seems a bit too complex in my opinion  Also  remember that the dot is a special character meaning  any character   The following regex should work  note the escaped dots          jpg JPG gif GIF doc DOC pdf PDF     You can use a tool like Expresso to test your regular expressions

User · Answer

You can use this template for every file type   ValidationExpression          pP  dD  fF     jJ  pP  gG     pP  nN  gG         for ex  you can add   rR  aA  rR   for Rar file type and etc

User · Answer

dD  oO  cC  xX        pP  dD  fF       Will accept  doc   docx   pdf files having a filename of at least one character                 beginning of string               at least one character  any character                dot          pattern    match the pattern without storing the match   dD           any character in the set   d  or  D    xX           any character in the set or none                  x  may be missing so  doc  or  docx  are both accepted                either the previous or the next pattern               end of matched string   Warning  Without enclosing the whole chain of extensions in       an extension like  docpdf would pass   You can test regular expressions at http   www regextester com

[c#] Validating file types by regular expression

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