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SCANF(3S)										SCANF(3S)

       scanf, fscanf, sscanf - formatted input conversion

       #include <stdio.h>

       scanf(format [ , pointer ] . . .  )
       char *format;

       fscanf(stream, format [ , pointer ] . . .  )
       FILE *stream;
       char *format;

       sscanf(s, format [ , pointer ] . . .  )
       char *s, *format;

       Scanf  reads  from  the	standard  input  stream stdin.	Fscanf reads from the named input
       stream.	Sscanf reads from the character string s.  Each function reads characters, inter-
       prets  them  according to a format, and stores the results in its arguments.  Each expects
       as arguments a control string format, described below, and  a  set  of  pointer	arguments
       indicating where the converted input should be stored.

       The  control  string  usually contains conversion specifications, which are used to direct
       interpretation of input sequences.  The control string may contain:

       1.  Blanks, tabs or newlines, which match optional white space in the input.

       2.  An ordinary character (not %) which must match the next character of the input stream.

       3.  Conversion specifications, consisting of the character %, an optional assignment  sup-
	   pressing  character	*,  an	optional  numerical maximum field width, and a conversion

       A conversion specification directs the conversion of the next input field; the  result  is
       placed  in  the	variable pointed to by the corresponding argument, unless assignment sup-
       pression was indicated by *.  An input field is defined as a string of  non-space  charac-
       ters;  it  extends to the next inappropriate character or until the field width, if speci-
       fied, is exhausted.

       The conversion character indicates the interpretation of the input field; the  correspond-
       ing pointer argument must usually be of a restricted type.  The following conversion char-
       acters are legal:

       %   a single `%' is expected in the input at this point; no assignment is done.

       d   a decimal integer is  expected;  the  corresponding	argument  should  be  an  integer

       o   an octal integer is expected; the corresponding argument should be a integer pointer.

       x   a  hexadecimal  integer  is	expected; the corresponding argument should be an integer

       s   a character string is expected; the	corresponding  argument  should  be  a	character
	   pointer  pointing  to  an  array of characters large enough to accept the string and a
	   terminating `\0', which will be added.  The input field is terminated by a space char-
	   acter or a newline.

       c   a  character  is  expected;	the corresponding argument should be a character pointer.
	   The normal skip over space characters is suppressed in this case;  to  read	the  next
	   non-space character, try `%1s'.  If a field width is given, the corresponding argument
	   should refer to a character array, and the indicated number of characters is read.

       e   a floating point number is expected; the  next  field  is  converted  accordingly  and
       f   stored  through the corresponding argument, which should be a pointer to a float.  The
	   input format for floating point numbers is an optionally signed string of digits  pos-
	   sibly containing a decimal point, followed by an optional exponent field consisting of
	   an E or e followed by an optionally signed integer.

       [   indicates a string not to be delimited by space characters.	The left bracket is  fol-
	   lowed  by a set of characters and a right bracket; the characters between the brackets
	   define a set of characters making up the string.  If the first character is	not  cir-
	   cumflex  (^),  the  input field is all characters until the first character not in the
	   set between the brackets; if the first character after the  left  bracket  is  ^,  the
	   input  field is all characters until the first character which is in the remaining set
	   of characters between the brackets.	The corresponding argument must point to a  char-
	   acter array.

       The conversion characters d, o and x may be capitalized or preceeded by l to indicate that
       a pointer to long rather than to int is in the argument list.  Similarly,  the  conversion
       characters  e  or  f  may  be capitalized or preceded by l to indicate a pointer to double
       rather than to float.  The conversion characters d, o and x may be preceeded by h to indi-
       cate a pointer to short rather than to int.

       The  scanf  functions  return the number of successfully matched and assigned input items.
       This can be used to decide how many input items were found.  The constant EOF is  returned
       upon  end of input; note that this is different from 0, which means that no conversion was
       done; if conversion was intended, it was frustrated by an inappropriate character  in  the

       For example, the call

		 int i; float x; char name[50];
		 scanf( "%d%f%s", &i, &x, name);

       with the input line

	      25   54.32E-1  thompson

       will assign to i the value 25, x the value 5.432, and name will contain `thompson\0'.  Or,

	      int i; float x; char name[50];
	      scanf("%2d%f%*d%[1234567890]", &i, &x, name);

       with input

	      56789 0123 56a72

       will  assign  56  to i, 789.0 to x, skip `0123', and place the string `56\0' in name.  The
       next call to getchar will return `a'.

       atof(3), getc(3), printf(3)

       The scanf functions return EOF on end of input, and a short count for missing  or  illegal
       data items.

       The success of literal matches and suppressed assignments is not directly determinable.

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