The Ring programming language version 1.5.3 book - Part 35 of 184

1. Ring Documentation, Release 1.5.3
42.40 permutation() function
Generates all permutations of n different numerals.
Syntax:
permutation(list)
Example:
Load "stdlib.ring"
# Generates all permutations of n different numerals
Puts("Test Permutation()")
list = [1, 2, 3, 4]
for perm = 1 to 24
for i = 1 to len(list)
see list[i] + " "
next
see nl
Permutation(list)
next
42.41 readline() function
Read line from file
Syntax:
readline(fp) ---> string
Example:
Load "stdlib.ring"
# Read a file line by line.
Puts("Test Readline()")
fp = fopen("test.ring","r")
while not feof(fp)
See Readline(fp) end
fclose(fp)
42.42 substring() function
Return a position of a substring starting from a given position in a string.
Syntax:
Substring(str,substr,npos) ---> string
Example:
Load "stdlib.ring"
# Return a position of a substring starting from a given position in a string.
42.40. permutation() function 315

2. Ring Documentation, Release 1.5.3
Puts("Test Substring()")
a = "abcxyzqweabc"
b = "abc"
i = 4
see substring(a,b,i)
42.43 changestring() function
Change substring from given position to a given position with another substring.
Syntax:
Changestring(cString, nPos1, nPos2, cSubstr) ---> cString
Example:
Load "stdlib.ring"
# Change substring from given position for given position with a substring.
Puts("Test Changestring()")
see Changestring("Rmasdg",2,5,"in") # Ring
42.44 sleep() function
Sleep for the given amount of time.
Syntax:
sleep(nSeconds)
Example:
Load "stdlib.ring"
Puts("Test Sleep()")
see "Wait 3 Seconds!"
Sleep(3)
see nl
42.45 ismainsourcefile() function
Check if the current file is the main source file
Syntax:
IsMainSourceFile() ---> True/False
Example:
Load "stdlib.ring"
if ismainsourcefile()
# code
ok
42.43. changestring() function 316

3. Ring Documentation, Release 1.5.3
42.46 direxists() function
Check if directory exists
Syntax:
DirExists(String) ---> True/False
Example:
Load "stdlib.ring"
see "Check dir : b:ring "
puts( DirExists("b:ring") )
see "Check dir : C:ring "
Puts( DirExists("C:ring") )
42.47 makedir() function
Make Directory
Syntax:
MakeDir(String)
Example:
Load "stdlib.ring"
# Create Directory
puts("create Directory : myfolder")
makedir("myfolder")
42.48 fsize() function
The function return the file size in bytes.
Syntax:
FSize(File Handle) ---> Number (File Size in Bytes)
42.49 trimall() function
Remove all spaces and tabs characters from a string
Syntax:
TrimAll(cString) ---> cString # Without Spaces and Tabs
42.46. direxists() function 317

4. Ring Documentation, Release 1.5.3
42.50 trimleft() function
Remove all spaces and tabs characters from the left side of a string
Syntax:
TrimLeft(cString) ---> cString # Without Spaces and Tabs from the left side
42.51 trimright() function
Remove all spaces and tabs characters from the right side of a string
Syntax:
TrimRight(cString) ---> cString # Without Spaces and Tabs from the right side
42.52 epochtime() function
Return the Epoch Time
Syntax:
EpochTime(cDate,cTime) ---> nEpochTime
Example:
see EpochTime( Date(), Time() )
42.53 SystemCmd() Function
We can execute system commands using the SystemCmd() function that outputs to a variable
Syntax:
SystemCmd(cCommand)
Example:
cYou = SystemCmd("whoami") # User Name logged in is output a variable
cThem = SystemCmd("dir c:Users") # Directory List is output to a variable
42.54 ListAllFiles() Function
Using this function we can quickly do a process on a group of files in a folder and it’s sub folders.
Syntax:
ListAllFiles(cFolder,cExtension) ---> List of Files
Example:
42.50. trimleft() function 318

5. Ring Documentation, Release 1.5.3
aList = ListAllFiles("c:/ring/ringlibs","ring") # *.ring only
aList = sort(aList)
see aList
Example:
see listallfiles("b:/ring/ringlibs/weblib","") # All Files
42.54. ListAllFiles() Function 319

6. CHAPTER
FORTYTHREE
STDLIB CLASSES
In this chapter we are going to learn about the classes in the stdlib.ring
• StdBase Class
• String Class
• List Class
• Stack Class
• Queue Class
• HashTable Class
• Tree Class
• Math Class
• DateTime Class
• File Class
• System Class
• Debug Class
• DataType Class
• Conversion Class
• ODBC CLass
• MySQL Class
• SQLite Class
• Security Class
• Internet Class
43.1 StdBase Class
Attributes:
• vValue : Object Value
Methods:
320

7. Ring Documentation, Release 1.5.3
Method Description/Output
Init(x) Set vValue Attribute to x value
Print() Print vValue
PrintLn() Print vValue then New Line
Size() return number represent the size of vValue
Value() return vValue
Set(x) Call Init(x)
43.2 String Class
Parent Class : StdBase Class
Methods:
Method Description/Output
Init(String|Number|List)
Lower() New String - Lower case characters
Upper() New String - Upper case characters
Left(x) New String - contains x characters from the left
Right(x) New String - contains x characters from the right
Lines() Number - Lines count
Trim() New String - Remove Spaces
Copy(x) New String - repeat string x times
strcmp(cString) Compare string with cString
tolist() List (String Lines to String Items)
tofile(cFileName) Write string to file
mid(nPos1,nPos2) New String - from nPos1 to nPos2
getfrom(nPos1) New String - from nPos1 to the end of the string
replace(cStr1,cStr2,lCase) New String - Replace cStr1 with cStr2 , lCase (True=Match Case)
split() List - Each Word as list item
startswith(substring) Return true if the start starts with a substring
endswith(substring) Return true if the start ends with a substring
Example:
Load "stdlib.ring"
See "Testing the String Class" + nl
oString = new string("Hello, World!")
oString.println()
oString.upper().println()
oString.lower().println()
oString.left(5).println()
oString.right(6).println()
oString = new string("Hi" + nl + "Hello" )
See oString.lines() + nl
oString = new string(" Welcome ")
oString.println()
oString.trim().println()
oString = new string("Hello! ")
oString.copy(3).println()
see oString.strcmp("Hello! ") + nl
see oString.strcmp("Hello ") + nl
see oString.strcmp("Hello!! ") + nl
oString = new string(["one","two","three"])
43.2. String Class 321

8. Ring Documentation, Release 1.5.3
oString.print()
see oString.lines() + nl
oString = new String(1234)
oString.println()
oString = new String("one"+nl+"two"+nl+"three")
aList = oString.tolist()
see "List Items" + nl See aList
oString = new String( "Welcome to the Ring programming language")
See "the - position : " + oString.pos("the") + nl
oString = oString.getfrom(oString.pos("Ring"))
oString.println()
oString.mid(1,4).println()
oString = oString.replace("Ring","***Ring***",true)
oString.println()
oString = oString.replace("ring","***Ring***",false)
oString.println()
oString1 = new string("First")
oString2 = new string("Second")
oString = oString1 + oString2
oString.println()
oString = oString1 * 3
oString.println()
for t in ostring see t next
oString.tofile("test.txt")
oString = new string("one two three")
see nl
see ostring.split()
oString {
set("Hello") println()
set("How are you?") println()
}
Output:
Testing the String Class
Hello, World!
HELLO, WORLD!
hello, world!
Hello
World!
2
Welcome
Welcome
Hello! Hello! Hello!
0
1
-1
one
two
three
4
1234
List Items
one
two
three
the - position : 12
Ring programming language
43.2. String Class 322

9. Ring Documentation, Release 1.5.3
Ring
***Ring*** programming language
******Ring****** programming language
FirstSecond
FirstFirstFirst
FirstFirstFirst
one
two
three
Hello
How are you?
43.3 List Class
Parent Class : StdBase Class
Methods:
Method Description/Output
Init(String|List)
Add(Value) Add item to the list
Delete(nIndex) Delete item from the list
Item(nIndex) Get item from the list
First() Get the first item in the list
Last() Get the last item in the list
Set(nIndex,Value) Set item value
FindInColumn(nCol,Value) Find item in a column
Sort() Sort items - return new list
Reverse() Reverse items - return new list
Insert(nIndex,Value) Inset Item after nIndex
example:
Load "stdlib.ring"
oList = new list ( [1,2,3] )
oList.Add(4)
oList.print()
see oList.item(1) + nl
oList.delete(4)
oList.print()
see oList.first() + nl
see oList.last() + nl
oList { set(1,"one") set(2,"two") set(3,"three") print() }
see oList.find("two") + nl
oList.sort().print()
oList.reverse().print()
oList.insert(2,"nice")
oList.print()
oList = new list ( [ [1,"one"],[2,"two"],[3,"three"] ] )
see copy("*",10) + nl
oList.print()
see "Search two : " + oList.findincolumn(2,"two") + nl
see "Search 1 : " + oList.findincolumn(1,1) + nl
oList = new list ( [ "Egypt" , "USA" , "KSA" ] )
for x in oList
43.3. List Class 323

10. Ring Documentation, Release 1.5.3
see x + nl
next
oList = new list ( [1,2,3,4] )
oList + [5,6,7]
oList.print()
oList = new list ( ["one","two"] )
oList2 = new list ( ["three","four"] )
oList + oList2
oList.print()
output:
1
2
3
4
1
1
2
3
1
3
one
two
three
2
one
three
two
three
two
one
one
two
nice
three
**********
1
one
2
two
3
three
Search two : 2
Search 1 : 1
Egypt
USA
KSA
1
2
3
4
5
6
7
one
two
three
43.3. List Class 324