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However, redirect logs to file can be called when command line options are parsed to
redirect normal and debug logs to a file named filename. In case filename is “-”, the logs are
redirected to standard output.
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hsrvflags.ml 175ai+≡
/ 175c 176b .
let redirect_logs_to_file () =
if !flag_log_filename = "" then
failwith "internal error: Srvflags.redirect_logs_to_file";
if !flag_log_filename = "-" then (
log_formatter := Format.std_formatter;
debug_formatter := Format.std_formatter
) else (
try
let oc = open_out !flag_log_filename in
let fmt = Format.formatter_of_out_channel oc in
log_formatter := fmt;
debug_formatter := fmt
with Sys_error str ->
Format.eprintf
"ERROR: cannot open log file ’%s’: %s\n" !flag_log_filename str
)
Helper function current time as string returns current time in international ISO-8601
string format.
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hsrvflags.ml 175ai+≡
let current_time_as_iso_string () =
Time.time_as_localtime_iso_string (Unix.time ())
/ 176a 176c .
We define the helper function dbg which prints on output its arguments only if flag debug
is true. dbg can be used in the same way as printf.
The trick here is to call kprintf as last expression in the function: http://caml.inria.fr/archives/
200405/msg00355.html.
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hsrvflags.ml 175ai+≡
let dbg fmt =
let print_if_necessary str =
if !flag_debug then (
let id = Thread.id (Thread.self ()) in
Format.fprintf !debug_formatter
"<%d>%s@[ %s@]@." id (current_time_as_iso_string ()) str;
) in
Format.kprintf print_if_necessary fmt
/ 176b 176d .
Helper function log is similar to dbg, but print its output to standard output.
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hsrvflags.ml 175ai+≡
let log fmt =
let print str =
let id = Thread.id (Thread.self ()) in
Format.fprintf !log_formatter
"<%d>%s@[ %s@]@." id (current_time_as_iso_string ()) str in
Format.kprintf print fmt
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