How to catch and error message and how to make it create unix files instead of dos files??
I am trying to write a small software to take info from one file and write it into another file. The problem is that when I don't give any input I get the normal haskell nosuchfile error message but I want to give my own error message. I am a newbie, how can I do that? Also I need the file that is gonna be created (A text file), to be created in UNIX type and not as a DOS file type, how can I do that? I am using ghc to compile on Windows. Here is the main code main :: IO() main = do args <- getArgs codes <- codes args conax <- readconax "conax.txt" makeIrdFile (lines codes) (lines conax) --Read input file------------------------------------ codes :: [String] -> IO[Char] codes [] = return "" codes (x:xs) = do first <- readFile x return first --Read Inbuilt file--------------------------------- readconax file = do list <- readFile file return list
Look at the functions try catch and bracket. -- Hal Daume III | hdaume@isi.edu "Arrest this man, he talks in maths." | www.isi.edu/~hdaume On Sat, 1 Mar 2003, Alexandre Weffort Thenorio wrote:
I am trying to write a small software to take info from one file and write it into another file. The problem is that when I don't give any input I get the normal haskell nosuchfile error message but I want to give my own error message. I am a newbie, how can I do that? Also I need the file that is gonna be created (A text file), to be created in UNIX type and not as a DOS file type, how can I do that? I am using ghc to compile on Windows.
Here is the main code
main :: IO() main = do args <- getArgs codes <- codes args conax <- readconax "conax.txt" makeIrdFile (lines codes) (lines conax)
--Read input file------------------------------------ codes :: [String] -> IO[Char] codes [] = return "" codes (x:xs) = do first <- readFile x return first
--Read Inbuilt file--------------------------------- readconax file = do list <- readFile file return list
Thanks I actually have done that but couldn't understand how to use them. Can you give me an example on a function that reads a file and in case the file is not found you throw a string like "File not found" or so?? Best Regards NooK ----- Original Message ----- From: "Hal Daume III" <hdaume@ISI.EDU> To: "Alexandre Weffort Thenorio" <thenorio@home.se> Cc: <haskell@haskell.org> Sent: Sunday, March 02, 2003 3:11 AM Subject: Re: How to catch and error message and how to make it create unix files instead of dos files??
Look at the functions try catch and bracket.
-- Hal Daume III | hdaume@isi.edu "Arrest this man, he talks in maths." | www.isi.edu/~hdaume
On Sat, 1 Mar 2003, Alexandre Weffort Thenorio wrote:
I am trying to write a small software to take info from one file and write it into another file. The problem is that when I don't give any input I get the normal haskell nosuchfile error message but I want to give my own error message. I am a newbie, how can I do that? Also I need the file that is gonna be created (A text file), to be created in UNIX type and not as a DOS file type, how can I do that? I am using ghc to compile on Windows.
Here is the main code
main :: IO() main = do args <- getArgs codes <- codes args conax <- readconax "conax.txt" makeIrdFile (lines codes) (lines conax)
--Read input file------------------------------------ codes :: [String] -> IO[Char] codes [] = return "" codes (x:xs) = do first <- readFile x return first
--Read Inbuilt file--------------------------------- readconax file = do list <- readFile file return list
_______________________________________________ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
main = do v <- try $ readFile "foo" case v of Left _ -> putStrLn "an error occurred" Right t -> putStrLn t should work -- Hal Daume III | hdaume@isi.edu "Arrest this man, he talks in maths." | www.isi.edu/~hdaume On Sun, 2 Mar 2003, Alexandre Weffort Thenorio wrote:
Thanks I actually have done that but couldn't understand how to use them. Can you give me an example on a function that reads a file and in case the file is not found you throw a string like "File not found" or so??
Best Regards
NooK
----- Original Message ----- From: "Hal Daume III" <hdaume@ISI.EDU> To: "Alexandre Weffort Thenorio" <thenorio@home.se> Cc: <haskell@haskell.org> Sent: Sunday, March 02, 2003 3:11 AM Subject: Re: How to catch and error message and how to make it create unix files instead of dos files??
Look at the functions try catch and bracket.
-- Hal Daume III | hdaume@isi.edu "Arrest this man, he talks in maths." | www.isi.edu/~hdaume
On Sat, 1 Mar 2003, Alexandre Weffort Thenorio wrote:
I am trying to write a small software to take info from one file and write it into another file. The problem is that when I don't give any input I get the normal haskell nosuchfile error message but I want to give my own error message. I am a newbie, how can I do that? Also I need the file that is gonna be created (A text file), to be created in UNIX type and not as a DOS file type, how can I do that? I am using ghc to compile on Windows.
Here is the main code
main :: IO() main = do args <- getArgs codes <- codes args conax <- readconax "conax.txt" makeIrdFile (lines codes) (lines conax)
--Read input file------------------------------------ codes :: [String] -> IO[Char] codes [] = return "" codes (x:xs) = do first <- readFile x return first
--Read Inbuilt file--------------------------------- readconax file = do list <- readFile file return list
_______________________________________________ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
_______________________________________________ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
participants (3)
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Alexandre Weffort Thenorio -
Alexandre Weffort Thenorio -
Hal Daume III