NAME

       Stdlib.Printf - no description

Module

       Module   Stdlib.Printf

Documentation

       Module Printf
        : (module Stdlib__printf)

       val fprintf : out_channel -> ('a, out_channel, unit) 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 channel, 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,  followed  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 decimal.  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 lowercase letters.

       - X : convert an integer argument to unsigned hexadecimal, using uppercase 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). Moreover, any trailing zeros are removed from the fractional
       part of the result and the decimal-point character is removed if there  is  no  fractional
       part remaining.

       -  h  or  H  :  convert  a  floating-point  argument to hexadecimal notation, in the style
       0xh.hhhh e+-dd (hexadecimal mantissa, exponent in decimal and denotes a power of 2).

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

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

       - 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   conversion
       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 integer types ( x , X , o , lx , lX ,
       lo , Lx , LX , Lo , d , i , u , ld , li , lu , Ld , Li , Lu , nd , ni , nu ).

       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 conversions. 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 corresponding width or precision .  This  integer
       argument  precedes  immediately  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, out_channel, unit) format -> 'a

       Same as Printf.fprintf , but output on stdout .

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

       Same as Printf.fprintf , but output on stderr .

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

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

       val ifprintf : 'b -> ('a, 'b, 'c, unit) format4 -> 'a

       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  : (out_channel -> 'd) -> out_channel -> ('a, out_channel, unit, 'd) format4
       -> 'a

       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 : ('b -> 'd) -> 'b -> ('a, 'b, 'c, 'd) format4 -> 'a

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

       Since 4.01.0

       val ksprintf : (string -> 'd) -> ('a, unit, string, 'd) format4 -> 'a

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

       Since 3.09.0

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

       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 -> 'b) -> ('a, unit, string, 'b) format4 -> 'a

       A deprecated synonym for ksprintf .