# The Regular exp read from file not matching! **URL:** \ **Category:** Ruby\ **Created:** [July 14, 2008, 9:40am UTC](https://www.ruby-forum.com/t/the-regular-exp-read-from-file-not-matching/142991 "2008-07-14T09:40:59Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![shambolic](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e36b37/32.png) [@shambolic](https://www.ruby-forum.com/u/shambolic)\ **Post date:** [July 14, 2008, 9:40am UTC](https://www.ruby-forum.com/t/the-regular-exp-read-from-file-not-matching/142991/1 "2008-07-14T09:40:59Z")
I am trying to read the syntax(here the regular expression) frpm a file. When I use /^[0-1]{1}$/ with “1” as subject it works but /^[0-1]{1}[a-zA-Z]{1,25}$/ syntax for “1,abcd” , I have checked out on the interpreter directly both works fine. I suppose I am messing up something with the files, or gets or chomp or … Any help ? ``` def sanity_check(param) filename = create_filename("Syntax",param) #this fn gets a ``` valid file name if File.exist?(filename) File.open(filename,“r+”) do |syntaxfile| syntax = syntaxfile.gets.chomp return syntax.match(@newsettings.value) end end return true # RETURN TRUE IF SYNTAX FILE NOT FOUND end ============================================================================== setprm\_0.1.2.rb:149: return value (rdb:1) v l filename =\> “C:\rubypgm\Paramsyntax\prm.102” param =\> “102” syntax =\> “/^[0-1]{1}[a-zA-Z]{1,25}$/” value =\> nil (rdb:1) n setprm\_0.1.2.rb:85: update\_status(("\n Incorrect syntax , File not up ---
**Author:** ![shambolic](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e36b37/32.png) [@shambolic](https://www.ruby-forum.com/u/shambolic)\ **Post date:** [July 14, 2008, 2:19pm UTC](https://www.ruby-forum.com/t/the-regular-exp-read-from-file-not-matching/142991/2 "2008-07-14T14:19:28Z")
On 14.07.2008, at 09:38, Jayan Jacob wrote: > When I use /^[0-1]{1}$/ with “1” as subject it works but > /^[0-1]{1}[a-zA-Z]{1,25}$/ syntax for “1,abcd” , I have checked out on > the interpreter directly both works fine. I suppose I am messing up > something with the files, or gets or chomp or … > > Any help ? That RegEx: /^[0-1]{1}[a-zA-Z]{1,25}$/ doesn’t match ‘,’. maybe: add ‘,’ irb\> regex2=/^[0-1]{1},[a-zA-Z]{1,25}$/ =\> /^[0-1]{1},[a-zA-Z]{1,25}$/ irb\> regex2.match “1,abcd” =\> #\ or ‘.?’ irb\> regex3=/^[0-1]{1}.?[a-zA-Z]{1,25}$/ =\> /^[0-1]{1}.?[a-zA-Z]{1,25}$/ irb\> regex3.match “1,abcd” =\> #\ hth. regards, Sandor Szücs ---
**Author:** ![shambolic](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e36b37/32.png) [@shambolic](https://www.ruby-forum.com/u/shambolic)\ **Post date:** [July 15, 2008, 4:17am UTC](https://www.ruby-forum.com/t/the-regular-exp-read-from-file-not-matching/142991/3 "2008-07-15T04:17:04Z")
Sorry for the typo error in the earlier mail , I did try “1abcd” on /^[0-1]{1}[a-zA-Z]{1,25}$/. I am putting a regular expression in a file and my program picks up this string to do a match with the input an string ==\> “syntax.match(@newsettings.value)” here is the debug info for more clarity (rdb:1) n setprm\_0.1.2.rb:149: return value (rdb:1) v l filename =\> “C:\rubypgm\Paramsyntax\prm.102” newsettings =\> “1abcd” param =\> “102” syntax =\> “/^[0-1]{1}[a-zA-Z]{1,25}$/” syntaxfile =\> #\ value =\> nil (rdb:1) l [144, 153] in setprm\_0.1.2.rb 144 if File.exist?(filename) 145 File.open(filename,“r+”) do |syntaxfile| 146 syntax = syntaxfile.gets.chomp 147 newsettings = @newsettings.value 148 value = syntax.match(newsettings) =\> 149 return value 150 end 151 end 152 return true # RETURN TRUE IF SYNTAX FILE NOT FOUND 153 end thanks jn Jay Jkb wrote: > I am trying to read the syntax(here the regular expression) frpm a file. > > When I use /^[0-1]{1}$/ with “1” as subject it works but > /^[0-1]{1}[a-zA-Z]{1,25}$/ syntax for “1,abcd” , I have checked out on > the interpreter directly both works fine. I suppose I am messing up > something with the files, or gets or chomp or … > > Any help ? > > ``` > def sanity_check(param) > filename = create_filename("Syntax",param) #this fn gets a > > ``` > > valid file name > if File.exist?(filename) > File.open(filename,“r+”) do |syntaxfile| > syntax = syntaxfile.gets.chomp > return syntax.match(@newsettings.value) > end > end > return true # RETURN TRUE IF SYNTAX FILE NOT FOUND > end > > ============================================================================== > > setprm\_0.1.2.rb:149: return value > (rdb:1) v l > filename =\> “C:\rubypgm\Paramsyntax\prm.102” > param =\> “102” > syntax =\> “/^[0-1]{1}[a-zA-Z]{1,25}$/” > value =\> nil > (rdb:1) n > setprm\_0.1.2.rb:85: update\_status(("\n Incorrect syntax , > File not up ---
**Author:** ![shambolic](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e36b37/32.png) [@shambolic](https://www.ruby-forum.com/u/shambolic)\ **Post date:** [July 15, 2008, 5:12am UTC](https://www.ruby-forum.com/t/the-regular-exp-read-from-file-not-matching/142991/4 "2008-07-15T05:12:00Z")
I replaced the code with return /#{syntaxfile.gets.chomp}/.match(@newsettings.value) and it worked. for some reason when i assign it to the variable syntax and then use it id does not work … some explanation on why? , would be great . thanx Jn Jay Jkb wrote: > I am trying to read the syntax(here the regular expression) frpm a file. > > When I use /^[0-1]{1}$/ with “1” as subject it works but > /^[0-1]{1}[a-zA-Z]{1,25}$/ syntax for “1,abcd” , I have checked out on > the interpreter directly both works fine. I suppose I am messing up > something with the files, or gets or chomp or … > > Any help ? > > ``` > def sanity_check(param) > filename = create_filename("Syntax",param) #this fn gets a > > ``` > > valid file name > if File.exist?(filename) > File.open(filename,“r+”) do |syntaxfile| > syntax = syntaxfile.gets.chomp > return syntax.match(@newsettings.value) > end > end > return true # RETURN TRUE IF SYNTAX FILE NOT FOUND > end > > ============================================================================== > > setprm\_0.1.2.rb:149: return value > (rdb:1) v l > filename =\> “C:\rubypgm\Paramsyntax\prm.102” > param =\> “102” > syntax =\> “/^[0-1]{1}[a-zA-Z]{1,25}$/” > value =\> nil > (rdb:1) n > setprm\_0.1.2.rb:85: update\_status(("\n Incorrect syntax , > File not up ---
**Author:** ![shambolic](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e36b37/32.png) [@shambolic](https://www.ruby-forum.com/u/shambolic)\ **Post date:** [July 15, 2008, 11:55am UTC](https://www.ruby-forum.com/t/the-regular-exp-read-from-file-not-matching/142991/5 "2008-07-15T11:55:53Z")
On 15.07.2008, at 05:07, Jay Jkb wrote: > some explanation on why? , would be great . In my opinion it’s a String vs. RegExp problem. Your rdebug output said that your syntax variable was a String, or?: > (rdb:1) v l > filename =\> “C:\rubypgm\Paramsyntax\prm.102” > newsettings =\> “1abcd” > param =\> “102” > syntax =\> “/^[0-1]{1}[a-zA-Z]{1,25}$/” syntax has doublequotes and is a String here (maybe a hint or just output?). However if you read from file you get a String not an Regexp you want to have a new Regexp so you have to use Regexp.new or /“string”/. In a test the String don’t match like a Regexp: irb\> syntax="/^[0-1]{1}[a-zA-Z]{1,25}$/" irb\> newsettings=“1abcd” irb\> syntax.match(newsettings) =\> nil irb\> syntax2=/^[0-1]{1}[a-zA-Z]{1,25}$/ irb\> syntax2.match(newsettings) =\> #\ you want: irb\> Regexp.new("/^[0-1]{1}[a-zA-Z]{1,25}$/") =\> //^[0-1]{1}[a-zA-Z] {1,25}$// or what you did: > /#{syntaxfile.gets.chomp}/.match(@newsettings.value) It’s a Regexp so it works as expected. hth. regards, Sandor Szücs