1Tcl_PrintDouble(3)          Tcl Library Procedures          Tcl_PrintDouble(3)
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NAME

8       Tcl_PrintDouble - Convert floating value to string
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SYNOPSIS

11       #include <tcl.h>
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13       Tcl_PrintDouble(interp, value, dst)
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ARGUMENTS

16       Tcl_Interp *interp (in)          Before   Tcl  8.0,  the  tcl_precision
17                                        variable  in  this  interpreter   con‐
18                                        trolled  the  conversion.   As  of Tcl
19                                        8.0, this argument is ignored and  the
20                                        conversion   is   controlled   by  the
21                                        tcl_precision  variable  that  is  now
22                                        shared by all interpreters.
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24       double value (in)                Floating-point value to be converted.
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26       char *dst (out)                  Where to store the string representing
27                                        value.  Must have  at  least  TCL_DOU‐
28                                        BLE_SPACE characters of storage.
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DESCRIPTION

33       Tcl_PrintDouble  generates  a string that represents the value of value
34       and stores it in memory at the location given by dst.  It uses %g  for‐
35       mat to generate the string, with one special twist: the string is guar‐
36       anteed to contain either a “.”  or an “e” so that it does not look like
37       an  integer.  Where %g would generate an integer with no decimal point,
38       Tcl_PrintDouble adds “.0”.                                              │
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40       If the tcl_precision value is non-zero, the result will have  precisely │
41       that  many digits of significance.  If the value is zero (the default), │
42       the result will have the fewest digits needed to represent  the  number │
43       in  such a way that Tcl_NewDoubleObj will generate the same number when │
44       presented with the given string.  IEEE semantics of  rounding  to  even │
45       apply to the conversion.
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KEYWORDS

49       conversion, double-precision, floating-point, string
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53Tcl                                   8.0                   Tcl_PrintDouble(3)
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