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# $Id: cl.fcl,v 1.1.1.1 2004/07/23 19:22:41 tang Exp $
# Scans its command line for various arguments.
# This is based upon example 'ape-05.l' (which is the flex version of
# 'ch2-05.l') from "lex & yacc" by John R. Levine, Tony Mason, and
# Doug Brown (by O'Reilly & Associates, ISBN 1-56592-000-7). For more
# information on using lex and yacc, see
# http://www.oreilly.com/catalog/lex/.
# myinput() could have been written much more efficiently because Tcl
# handles command line arguments as a list. For the sake of porting
# the original example to Tcl, I used the same logic found within the
# original flex code.
%{
#!/usr/bin/tclsh
%}
%buffersize 1024
%option nodefault
%%
-h |
-\? |
-help {
puts "usage is: $::progName \[-help | -h | -? \] \[-verbose | -v \] \[(-file | -f) filename\]"
# actually, the -f option is not handled by this program.
# that is left as an exercise to the reader.
}
-v |
-verbose {
puts "verbose mode is on"
set ::verbose 1
}
%%
proc YY_INPUT {buf result max} {
upvar $result ret_val
upvar $buf buf_data
set ret_val [myinput buf_data $max]
}
set ::offset 0
proc myinput {buf max} {
upvar $buf buf_data
if {[llength $::targv] == 0} {
# no arguments left, so return an EOF
return 0
}
set len [string length [lindex $::targv 0]]
if {$len >= $max} {
set copylen [expr {$max - 1}]
} else {
set copylen $len
}
if {$len > 0} {
set buf_data [string range [lindex $::targv 0] $::offset $copylen]
}
if {[string length [lindex $::targv 0]] >= $::offset + $copylen} {
append buf " "
incr copylen
set ::offset 0
set ::targv [lrange $::targv 1 end]
} else {
incr ::offset $copylen
}
return $copylen
}
set progName $argv0
set verbose 0
set ::targv $argv ;# holds remainder of argument list
yylex
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