erlang, writing integer values to a file

Question

I want to print integer values to a file. I am able to write string values to the file, but I try to write integer value it gives an error

%this works fine {ok, F}=file:open("bff.txt", [read,write]), Val="howdy", file:write(F,Val).

%this gets compiled, but results in error {error, badarg} while executing {ok, F}=file:open("bff.txt", [read,write]), Val=23424, file:write(F,Val).

Any suggestions ? Actually I want to write a benchmarking code for a web server and I need to write all the values of times and no of requests to an output file, and then I'll use it to plot graph with gnuplot.

Answer 1

Use integer_to_list/1 to convert integers to a list for file:write/2.

{ok, F}=file:open("bff.txt", [read,write]), 
Val=integer_to_list(23424), 
file:write(F,Val).

Answer 2

This is because file:write only can output strings. An alternative is to use functions in the io module which also work on files. So io:write(File, Val) will work. You can alternatively use formatted io functions io:format. It really depends how you wish to format the data and how they are to be read, just writing integers with io:write will not be very useful if you intend to read them.