diff options
Diffstat (limited to 'doc/scan.n')
| -rw-r--r-- | doc/scan.n | 56 |
1 files changed, 39 insertions, 17 deletions
@@ -6,10 +6,10 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: scan.n,v 1.7 2000/12/10 03:27:03 hobbs Exp $ +'\" RCS: @(#) $Id: scan.n,v 1.8 2002/02/15 14:28:48 dkf Exp $ '\" .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 @@ -28,13 +28,11 @@ to be parsed and \fIformat\fR indicates how to parse it, using \fB%\fR 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 @@ -46,10 +44,13 @@ Otherwise, if it isn't a \fB%\fR character then it 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 instead of assigned to a variable; a XPG3 position specifier; a number -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 @@ -75,33 +76,56 @@ The following conversion characters are supported: \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), it will be truncated to a signed integer. Hence, 037777777777 -will appear as -1 on a 32-bit machine. +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 8.4 +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), it will be truncated to a signed integer. Hence, 0xFFFFFFFF -will appear as -1 on a 32-bit machine. +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. +.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 @@ -177,16 +201,14 @@ 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 8.4 +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] -.VS 8.3 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) |