File exist

From Erlang Community

(Difference between revisions)
Revision as of 07:11, 15 October 2007 (edit)
Andreas.hillqvist (Talk | contribs)

← Previous diff		 Current revision (20:09, 18 October 2009) (edit) (undo)
Ayrnieu (Talk | contribs)
(redo; add race-condition warning.)
 
Line 1: Line 1:
-The function ''filelib:is_regular/1'' could be used to verify that an file do exist or dose not exist.+The function filelib:is_file/1 returns true if its argument refers to an existing file or directory. filelib:is_regular/1 more narrowly returns true on regular files.
-Here is a example: 
<code> <code>
-case filelib:is_regular(FileName) of+assert_config(Filename) ->
- true ->+ true = filelib:is_regular(Filename).
- io:format("File exist.\n");+ 
- false ->+
- io:format("File dose not exist.\n")+
-end+
</code> </code>
 +
 +Generally you should assume that files exist, are readable, etc. -- and gracefully handle your failures. You'll have to do this second part ''anyway'', as e.g. a file can be deleted after assert_config/1 succeeds and before your read_config/1 tries to open it.
 +
[[Category:CookBook]] [[Category:FileRecipes]] [[Category:CookBook]] [[Category:FileRecipes]]

Current revision

The function filelib:is_file/1 returns true if its argument refers to an existing file or directory. filelib:is_regular/1 more narrowly returns true on regular files. 

assert_config(Filename) ->
    true = filelib:is_regular(Filename).

Generally you should assume that files exist, are readable, etc. -- and gracefully handle your failures. You'll have to do this second part anyway, as e.g. a file can be deleted after assert_config/1 succeeds and before your read_config/1 tries to open it.

Retrieved from "http://www.trapexit.org/File_exist"
Erlang/OTP Projects
Personal tools