'\" RCS: @(#) $Id$
'\"
.so man.macros
-.TH scan n 8.3 Tcl "Tcl Built-In Commands"
+.TH scan n 8.4 Tcl "Tcl Built-In Commands"
.BS
'\" Note: do not modify the .SH NAME line immediately below!
.SH NAME
conversion specifiers as in \fBsscanf\fR. Each \fIvarName\fR gives the
name of a variable; when a field is scanned from \fIstring\fR the result is
converted back into a string and assigned to the corresponding variable.
-.VS 8.3
If no \fIvarName\fR variables are specified, then \fBscan\fR works in an
inline manner, returning the data that would otherwise be stored in the
variables as a list. In the inline case, an empty string is returned when
the end of the input string is reached before any conversions have been
performed.
-.VE 8.3
.SH "DETAILS ON SCANNING"
.PP
must match the next character of \fIstring\fR.
When a \fB%\fR is encountered in \fIformat\fR, it indicates
the start of a conversion specifier.
+.VS 8.4
A conversion specifier contains up to four fields after the \fB%\fR:
a \fB*\fR, which indicates that the converted value is to be discarded
-.VS 8.1
instead of assigned to a variable; a XPG3 position specifier; a number
-.VE 8.1
-indicating a maximum field width; and a conversion character.
+indicating a maximum field width; a field size modifier; and a
+conversion character.
+.VE 8.4
All of these fields are optional except for the conversion character.
The fields that are present must appear in the order given above.
.PP
Then it converts the next input characters according to the
conversion specifier and stores the result in the variable given
by the next argument to \fBscan\fR.
-.VS 8.1
.PP
If the \fB%\fR is followed by a decimal number and a \fB$\fR, as in
``\fB%2$d\fR'', then the variable to use is not taken from the next
list must correspond to exactly one conversion specifier or an error
is generated, or in the inline case, any position can be specified
at most once and the empty positions will be filled in with empty strings.
-.VE 8.1
.PP
The following conversion characters are supported:
.TP 10
\fBd\fR
The input field must be a decimal integer.
It is read in and the value is stored in the variable as a decimal string.
+.VS 8.4
+If the \fBl\fR or \fBL\fR field size modifier is given, the scanned
+value will have an internal representation that is at least 64-bits in
+size.
+.VE 8.4
.TP 10
\fBo\fR
The input field must be an octal integer. It is read in and the
value is stored in the variable as a decimal string.
+.VS 8.4
+If the \fBl\fR or \fBL\fR field size modifier is given, the scanned
+value will have an internal representation that is at least 64-bits in
+size.
+If the value exceeds MAX_INT (017777777777 on platforms using 32-bit
+integers when the \fBl\fR and \fBL\fR modifiers are not given), it
+will be truncated to a signed integer. Hence, 037777777777 will
+appear as -1 on a 32-bit machine by default.
+.VE 8.4
.TP 10
\fBx\fR
The input field must be a hexadecimal integer. It is read in
and the value is stored in the variable as a decimal string.
-.VS 8.1
+.VS 8.4
+If the \fBl\fR or \fBL\fR field size modifier is given, the scanned
+value will have an internal representation that is at least 64-bits in
+size.
+If the value exceeds MAX_INT (0x7FFFFFFF on platforms using 32-bit
+integers when the \fBl\fR and \fBL\fR modifiers are not given), it
+will be truncated to a signed integer. Hence, 0xFFFFFFFF will appear
+as -1 on a 32-bit machine.
+.VE 8.4
.TP 10
\fBu\fR
The input field must be a decimal integer. The value is stored in the
variable as an unsigned decimal integer string.
+.VS 8.4
+If the \fBl\fR or \fBL\fR field size modifier is given, the scanned
+value will have an internal representation that is at least 64-bits in
+size.
+.VE 8.4
.TP 10
\fBi\fR
The input field must be an integer. The base (i.e. decimal, octal, or
hexadecimal) is determined in the same fashion as described in
\fBexpr\fR. The value is stored in the variable as a decimal string.
-.VE 8.1
+.VS 8.4
+If the \fBl\fR or \fBL\fR field size modifier is given, the scanned
+value will have an internal representation that is at least 64-bits in
+size.
+.VE 8.4
.TP 10
\fBc\fR
A single character is read in and its binary value is stored in
If the first character between the brackets is a \fB]\fR then
it is treated as part of \fIchars\fR rather than the closing
bracket for the set.
-.VS 8.1
If \fIchars\fR
contains a sequence of the form \fIa\fB\-\fIb\fR then any
character between \fIa\fR and \fIb\fR (inclusive) will match.
If the first or last character between the brackets is a \fB\-\fR, then
it is treated as part of \fIchars\fR rather than indicating a range.
-.VE 8.1
.TP 10
\fB[^\fIchars\fB]\fR
The input field consists of any number of characters not in
If the character immediately following the \fB^\fR is a \fB]\fR then it is
treated as part of the set rather than the closing bracket for
the set.
-.VS 8.1
If \fIchars\fR
contains a sequence of the form \fIa\fB\-\fIb\fR then any
character between \fIa\fR and \fIb\fR (inclusive) will be excluded
.TP 10
\fBn\fR
No input is consumed from the input string. Instead, the total number
-of chacters scanned from the input string so far is stored in the variable.
-.VE 8.1
+of characters scanned from the input string so far is stored in the variable.
.LP
The number of characters read from the input for a conversion is the
largest number that makes sense for that particular conversion (e.g.
.PP
The behavior of the \fBscan\fR command is the same as the behavior of
the ANSI C \fBsscanf\fR procedure except for the following differences:
-.VS 8.1
.IP [1]
\fB%p\fR conversion specifier is not currently supported.
-.VE 8.1
.IP [2]
For \fB%c\fR conversions a single character value is
converted to a decimal string, which is then assigned to the
corresponding \fIvarName\fR;
no field width may be specified for this conversion.
.IP [3]
-The \fBl\fR, \fBh\fR, and \fBL\fR modifiers are ignored; integer
-values are always converted as if there were no modifier present
-and real values are always converted as if the \fBl\fR modifier
-were present (i.e. type \fBdouble\fR is used for the internal
-representation).
-.VS 8.3
+.VS 8.4
+The \fBh\fR modifier is always ignored and the \fBl\fR and \fBL\fR
+modifiers are ignored when converting real values (i.e. type
+\fBdouble\fR is used for the internal representation).
+.VE 8.4
.IP [4]
If the end of the input string is reached before any conversions have been
-performed and no variables are given, and empty string is returned.
-.VE 8.3
+performed and no variables are given, an empty string is returned.
+
+.SH "SEE ALSO"
+format(n), sscanf(3)
.SH KEYWORDS
conversion specifier, parse, scan
-
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