Basic Commands in Tcl(Tool Command Language)

Introduction

What is Tcl(Tool Command Language)

Basic Commands

#!/usr/bin/tclsh

# variable assign 

set {a} 10
set b 12
set c 14
set d "14"
set e [expr $d + 10 + 9]
set res1 [expr $e / 9];  # the result is interger,Notice the semicolon here
set res2 [expr $e/ 9.0]; # the result is float,Notice the semicolon here

# variable print
puts $a
puts ${a}
puts $b
puts ${b}
puts " $b "
puts [expr $c + 10 + 9 ]
puts [expr $d + 10 + 9 ]
puts $e
puts $res1
puts $res2

#===========================================
# Variable Type -String
#===========================================

##the default type is string
set s1 hello        
puts $s1


##use quotation marks
set s2 "hello world" 
puts $s2 


##use brace marks
set s3 {hello world} 
puts $s3


##escape charater
set s4 "\\  \' \" \? \a \b \f \n \r \t \v "
puts $s4


##string command 

puts [string compare $s1 $s2] 
puts [string compare $s2 "hello world"]
puts [string length $s1]
puts [string tolower $s1]
puts [string index  $s1 2]
## refer to the TCL manual for more other string related commands
## index,length,range,tplower,toupper,trimleft .etc..





#===========================================
# Variable Type -List
#===========================================




set list1 {a b c}
set list2 [list a b c]
set list3 [split "a_b_c" _]
puts $list1 
puts $list2
puts $list3

## index
puts [lindex $list3 2] 


## append
append list1 " " "d"
append list1 "d"
lappend list1 "d"
puts $list1


## length
puts [llength $list1]


## index
puts [lindex $list1 1]

## insert 
puts "insert"
set list1 [linsert $list1 3 hi asd asd]
puts $list1
##puts  [linsert $list1 3 hi asd asd]

## replace 
set list1 [lreplace $list1 1 1 hello ]
puts $list1

## set 
#puts [lset list1 0 world]

## assign 
#lassign list1 tmp_list1 tmp_list2
#puts $tmp_list1
#puts $tmp_list2

## sort 
set list1 [lsort $list1]
puts $list1


#================================
# Variable Type - Array
#================================

set array1(0) chen
set array1(1) weijie
puts $array1(0)
puts $array1(1)
puts [array size array1]
puts "iterats"
for { set index 0 }  { $index < [array size array1] }  { incr index } {
        puts "${index}"
        puts "$array1($index)"
}


set person1(age) 80
set person1(name) chen
foreach index [array names person1] { 
        puts "$index"
        puts "$person1($index)"
}




#=====================

#Variable Type - dict

#======================

##dict create d1 name chen  age 17

##dict set d2 name Jason
##dict set d2 age 18

##set d3 [dict create name Bob age 19]

###puts $d1
##puts $d2
##puts $d3
##puts [dict size $d1]

### refer to document for more details





#=====================
# Condition Statement 
#=====================


set a 30

if { $a == 10 } {

        puts "Value is 10"

} elseif { $a == 20 } {

        puts "Value is 20"

} else {

        puts "no matching value"
}





switch $a {

        10 {
         puts "the value is 10"
        }
        20 {
         puts "the value is 20"
        }
        default {
        puts "no matching value"
        }

}



set b [expr $a == 10 ? 10 : 20]
puts "the value of b is : $b \n"





#=====================

#Loop Stament

#=====================

while { $a < 40 } {
        incr a
        puts " the value of $a "
}


for { set index $b} { $index < 30 } { incr index } {

        puts " the value of index : $index "

        if { $index == 21 } {
                incr index
                continue
        }

        if { $index == 25 } {
                break
        }

}



#====================

#Proc

#====================

proc func1 {} {

        puts "hello world"

}

proc func2 { a b } {
        return [ expr $a + $b ]

}


proc func3 { numbers } {

        set sum 0 
        foreach number $numbers {
                set sum [ expr  $sum + $number ]
        }
        set avg [ expr $sum / [ llength  $numbers ]]
        return $avg
}


proc func4 { a { b 10 } } {

        return [ expr $a + $b ]
}

 

proc func5 { num } {
        if { $num == 1 } {
                return 1
        }

        return [ expr  $num * [ func5 [ expr $num -1 ]]]


}



func1

puts [ func2  10 20  ]

puts [func3  {10 20 30}]

puts [func4 10 ]

puts [ func4 10 20 ] 

puts [ func5 5 ]



#================

#NameSpace 

#===================



## define namespace 
namespace  eval MyMath {

        variable myResult

        namespace eval MyMath_Inner {

        variable myResult1

        }

}

## set the variable And proc of the namespace 
proc MyMath::Add { a b } {
        set ::MyMath::myResult [ expr $a + $b ]
        set ::MyMath::myResult1 [ expr $a - $b ]

}



## print the varible  And proc output of the namespace
MyMath::Add 10 23
puts $::MyMath::myResult
puts $::MyMath::myResult1




## export the porc of the namespace

namespace eval  testNamespace {

        namespace export testProc
}

proc testNamespace::testProc {a  b} {
        return  [expr $a * $b ]

}



namespace import testNamespace::* 
puts [ testProc 10 20 ] 
namespace forget testNamespace::* 





#=======================
#File IO
#=======================

## write file 

set fp [ open "FileIoTest" w+]
puts $fp "test"
close $fp 


## read file 
set fp [open "FileIoTest" r]
set content [read $fp]
puts $content
close $fp


# read file line by line

set fp [open "FileIoTest2" w+] 
puts $fp "hello \n world"
close $fp


set fp [open "FileIoTest2" r]
while { [gets $fp data] >0 } {
        puts $data
}
close $fp




#===================
#Error & Catch 
#===================


proc Div {a b} {
    if {$b == 0} {
  error "Error generated by error" "Info String for error" 401
    } else {
      return [expr $a/$b]
    }
}
if {[catch {puts "Result = [Div 10 0]"} errmsg]} {
   puts "ErrorMsg: $errmsg"
   puts "ErrorCode: $errorCode"
   puts "ErrorInfo:\n$errorInfo\n"
}

if {[catch {puts "Result = [Div 10 2]"} errmsg]} {
   puts "ErrorMsg: $errmsg"
   puts "ErrorCode: $errorCode"
   puts "ErrorInfo:\n$errorInfo\n"
}