manpagez: man pages & more
man Printf(3)
Home | html | info | man
Printf(3)                        OCaml library                       Printf(3)




NAME

       Printf - Formatted output functions.


Module

       Module   Printf


Documentation

       Module Printf
        : sig end


       Formatted output functions.






       val  fprintf  :  Pervasives.out_channel -> ('a, Pervasives.out_channel,
       unit) Pervasives.format -> 'a


       fprintf outchan format arg1 ... argN formats the arguments arg1 to argN
       according  to  the  format  string  format  , and outputs the resulting
       string on the channel outchan .

       The format string is a character string which  contains  two  types  of
       objects:  plain characters, which are simply copied to the output chan-
       nel, and conversion specifications, each of which causes conversion and
       printing of arguments.

       Conversion specifications have the following form:


       % [flags] [width] [.precision] type

       In  short, a conversion specification consists in the % character, fol-
       lowed by optional modifiers and a type which is  made  of  one  or  two
       characters.

       The types and their meanings are:


       - d , i : convert an integer argument to signed decimal.

       -  u , n , l , L , or N : convert an integer argument to unsigned deci-
       mal.  Warning: n , l , L , and N are used for scanf , and should not be
       used for printf .

       - x : convert an integer argument to unsigned hexadecimal, using lower-
       case letters.

       - X : convert an integer argument to unsigned hexadecimal, using upper-
       case letters.

       - o : convert an integer argument to unsigned octal.

       - s : insert a string argument.

       -  S  :  convert  a  string  argument  to  OCaml syntax (double quotes,
       escapes).

       - c : insert a character argument.

       - C : convert a character argument  to  OCaml  syntax  (single  quotes,
       escapes).

       -  f  :  convert  a floating-point argument to decimal notation, in the
       style dddd.ddd .

       - F : convert a floating-point argument to OCaml  syntax  (  dddd.   or
       dddd.ddd or d.ddd e+-dd ).

       -  e  or  E : convert a floating-point argument to decimal notation, in
       the style d.ddd e+-dd (mantissa and exponent).

       - g or G : convert a floating-point argument to  decimal  notation,  in
       style f or e , E (whichever is more compact).

       - B : convert a boolean argument to the string true or false


       -  b  :  convert a boolean argument (deprecated; do not use in new pro-
       grams).

       - ld , li , lu , lx , lX , lo : convert an int32 argument to the format
       specified by the second letter (decimal, hexadecimal, etc).

       -  nd  ,  ni  , nu , nx , nX , no : convert a nativeint argument to the
       format specified by the second letter.

       - Ld , Li , Lu , Lx , LX , Lo : convert an int64 argument to the format
       specified by the second letter.

       -  a : user-defined printer. Take two arguments and apply the first one
       to outchan (the current output channel) and to the second argument. The
       first  argument  must therefore have type out_channel -> 'b -> unit and
       the second 'b .  The output produced by the function is inserted in the
       output of fprintf at the current point.

       - t : same as %a , but take only one argument (with type out_channel ->
       unit ) and apply it to outchan .

       - { fmt %} : convert a format string argument to its type digest.   The
       argument must have the same type as the internal format string fmt .

       -  ( fmt %) : format string substitution. Take a format string argument
       and substitute it to the internal format string fmt to print  following
       arguments.  The argument must have the same type as the internal format
       string fmt .

       - !  : take no argument and flush the output.

       - % : take no argument and output one % character.

       - @ : take no argument and output one @ character.

       - , : take no argument and output nothing: a no-op delimiter  for  con-
       version specifications.

       The optional flags are:

       - - : left-justify the output (default is right justification).

       - 0 : for numerical conversions, pad with zeroes instead of spaces.

       -  + : for signed numerical conversions, prefix number with a + sign if
       positive.

       -space: for signed numerical conversions, prefix number with a space if
       positive.

       -  #  :  request  an alternate formatting style for the hexadecimal and
       octal integer types ( x , X , o , lx , lX , lo , Lx , LX , Lo ).

       The optional width is an integer indicating the minimal  width  of  the
       result.  For  instance, %6d prints an integer, prefixing it with spaces
       to fill at least 6 characters.

       The optional precision is a dot .  followed by  an  integer  indicating
       how  many  digits follow the decimal point in the %f , %e , and %E con-
       versions. For instance, %.4f prints a float with 4 fractional digits.

       The integer in a width or precision can also be specified  as  *  ,  in
       which  case  an  extra  integer argument is taken to specify the corre-
       sponding width or precision . This integer  argument  precedes  immedi-
       ately the argument to print.  For instance, %.*f prints a float with as
       many fractional digits as the value of the argument  given  before  the
       float.



       val printf : ('a, Pervasives.out_channel, unit) Pervasives.format -> 'a

       Same as Printf.fprintf , but output on stdout .



       val eprintf : ('a, Pervasives.out_channel, unit)  Pervasives.format  ->
       'a

       Same as Printf.fprintf , but output on stderr .



       val sprintf : ('a, unit, string) Pervasives.format -> 'a

       Same  as Printf.fprintf , but instead of printing on an output channel,
       return a string containing the result of formatting the arguments.



       val bprintf : Buffer.t -> ('a, Buffer.t, unit) Pervasives.format -> 'a

       Same as Printf.fprintf , but instead of printing on an output  channel,
       append the formatted arguments to the given extensible buffer (see mod-
       ule Buffer ).



       val ifprintf : 'a -> ('b, 'a, unit) Pervasives.format -> 'b

       Same as Printf.fprintf , but does not print anything.  Useful to ignore
       some material when conditionally printing.


       Since 3.10.0





       === Formatted output functions with continuations. ===



       val kfprintf : (Pervasives.out_channel -> 'a) -> Pervasives.out_channel
       -> ('b, Pervasives.out_channel, unit, 'a) Pervasives.format4 -> 'b

       Same as fprintf , but instead of returning immediately, passes the  out
       channel to its first argument at the end of printing.


       Since 3.09.0



       val  ikfprintf : (Pervasives.out_channel -> 'a) -> Pervasives.out_chan-
       nel -> ('b, Pervasives.out_channel, unit, 'a) Pervasives.format4 -> 'b

       Same as kfprintf above, but does not print anything.  Useful to  ignore
       some material when conditionally printing.


       Since 4.0



       val ksprintf : (string -> 'a) -> ('b, unit, string, 'a) Pervasives.for-
       mat4 -> 'b

       Same as sprintf above, but instead of returning the string,  passes  it
       to the first argument.


       Since 3.09.0



       val kbprintf : (Buffer.t -> 'a) -> Buffer.t -> ('b, Buffer.t, unit, 'a)
       Pervasives.format4 -> 'b

       Same as bprintf , but instead  of  returning  immediately,  passes  the
       buffer to its first argument at the end of printing.


       Since 3.10.0





       === Deprecated ===



       val  kprintf : (string -> 'a) -> ('b, unit, string, 'a) Pervasives.for-
       mat4 -> 'b

       A deprecated synonym for ksprintf .





OCamldoc                          2014-10-18                         Printf(3)

ocaml 4.02.1 - Generated Mon Oct 20 18:40:36 CDT 2014
© manpagez.com 2000-2024
Individual documents may contain additional copyright information.