The Ring programming language version 1.8 book - Part 30 of 202
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The document describes various functions for working with files in Ring programming language. Some of the key functions covered include Read() and Write() for reading from and writing to files, Dir() for getting directory listings, Rename() and Remove() for renaming and deleting files, Fopen() and Fclose() for opening and closing file handles, and Fseek(), Ftell(), Rewind() for manipulating the file position indicator. Functions for error handling like Feof(), Ferror(), Clearerr() and temporary files management are also discussed.
![Ring Documentation, Release 1.8
cosh(1) = 1.54
tanh(0) = 0
tanh(1) = 0.76
exp(0) = 1
exp(1) = 2.72
log(1) = 0
log(2) = 0.69
log10(1) = 0
log10(2) = 0.30
log10(10) = 1
Ceil(1.12) = 2
Ceil(1.72) = 2
Floor(1.12) = 1
Floor(1.72) = 1
fabs(1.12) = 1.12
fabs(1.72) = 1.72
pow(2,3) = 8
sqrt(16) = 4
33.3 Random() Function
The Random() function generate a random number and we can set the maximum value (optional).
Syntax:
Random(x) ---> Random number in the range [0,x]
Example:
for x = 1 to 20
see "Random number : " + random() + nl +
"Random number Max (100) : " + random(100) + nl
next
Program Output:
Random number : 31881
Random number Max (100) : 80
Random number : 5573
Random number Max (100) : 63
Random number : 2231
Random number Max (100) : 43
Random number : 12946
Random number Max (100) : 39
Random number : 22934
Random number Max (100) : 48
Random number : 4690
Random number Max (100) : 52
Random number : 13196
Random number Max (100) : 65
Random number : 30390
Random number Max (100) : 87
Random number : 4327
Random number Max (100) : 77
Random number : 12456
Random number Max (100) : 17
Random number : 28438
33.3. Random() Function 262](https://image.slidesharecdn.com/291ring-180826100809/85/The-Ring-programming-language-version-1-8-book-Part-30-of-202-2-320.jpg)
![Ring Documentation, Release 1.8
see "Testing DIR() " + nl
mylist = dir("C:myfolder")
for x in mylist
if x[2]
see "Directory : " + x[1] + nl
else
see "File : " + x[1] + nl
ok
next
see "Files count : " + len(mylist)
34.4 Rename() Function
We can rename files using the Rename() function
Syntax:
Rename(cOldFileName,cNewFileName)
Example:
rename("file.txt","help.txt")
34.5 Remove() Function
We can delete a file using the Remove() function
Syntax:
Remove(cFileName)
Example:
remove("test.txt")
34.6 Fopen() Function
We can open a file using the Fopen() function
Syntax:
Fopen(cFileName,cMode) ---> File Handle
Mode Description
“r” Reading (The file must exist)
“w” Writing (create empty file / overwrite)
“a” Appends (create file if it doesn’t exist)
“r+” update (reading/writing)
“w+” Create empty file (reading/writing)
“a+” reading & appending
34.4. Rename() Function 267](https://image.slidesharecdn.com/291ring-180826100809/85/The-Ring-programming-language-version-1-8-book-Part-30-of-202-7-320.jpg)
The Ring programming language version 1.8 book - Part 30 of 202
- 1. Ring Documentation, Release 1.8 See "Cos(90) degree = " + cos(90*3.14/180) + nl See "Tan(0) = " + tan(0) + nl See "Tan(90) radians = " + tan(90) + nl See "Tan(90) degree = " + tan(90*3.14/180) + nl See "asin(0) = " + asin(0) + nl See "acos(0) = " + acos(0) + nl See "atan(0) = " + atan(0) + nl See "atan2(1,1) = " + atan2(1,1) + nl See "sinh(0) = " + sinh(0) + nl See "sinh(1) = " + sinh(1) + nl See "cosh(0) = " + cosh(0) + nl See "cosh(1) = " + cosh(1) + nl See "tanh(0) = " + tanh(0) + nl See "tanh(1) = " + tanh(1) + nl See "exp(0) = " + exp(0) + nl See "exp(1) = " + exp(1) + nl See "log(1) = " + log(1) + nl See "log(2) = " + log(2) + nl See "log10(1) = " + log10(1) + nl See "log10(2) = " + log10(2) + nl See "log10(10) = " + log10(10) + nl See "Ceil(1.12) = " + Ceil(1.12) + nl See "Ceil(1.72) = " + Ceil(1.72) + nl See "Floor(1.12) = " + floor(1.12) + nl See "Floor(1.72) = " + floor(1.72) + nl See "fabs(1.12) = " + fabs(1.12) + nl See "fabs(1.72) = " + fabs(1.72) + nl See "pow(2,3) = " + pow(2,3) + nl see "sqrt(16) = " + sqrt(16) + nl Program Output: Mathematical Functions Sin(0) = 0 Sin(90) radians = 0.89 Sin(90) degree = 1.00 Cos(0) = 1 Cos(90) radians = -0.45 Cos(90) degree = 0.00 Tan(0) = 0 Tan(90) radians = -2.00 Tan(90) degree = 1255.77 asin(0) = 0 acos(0) = 1.57 atan(0) = 0 atan2(1,1) = 0.79 sinh(0) = 0 sinh(1) = 1.18 cosh(0) = 1 33.2. Example 261
- 2. Ring Documentation, Release 1.8 cosh(1) = 1.54 tanh(0) = 0 tanh(1) = 0.76 exp(0) = 1 exp(1) = 2.72 log(1) = 0 log(2) = 0.69 log10(1) = 0 log10(2) = 0.30 log10(10) = 1 Ceil(1.12) = 2 Ceil(1.72) = 2 Floor(1.12) = 1 Floor(1.72) = 1 fabs(1.12) = 1.12 fabs(1.72) = 1.72 pow(2,3) = 8 sqrt(16) = 4 33.3 Random() Function The Random() function generate a random number and we can set the maximum value (optional). Syntax: Random(x) ---> Random number in the range [0,x] Example: for x = 1 to 20 see "Random number : " + random() + nl + "Random number Max (100) : " + random(100) + nl next Program Output: Random number : 31881 Random number Max (100) : 80 Random number : 5573 Random number Max (100) : 63 Random number : 2231 Random number Max (100) : 43 Random number : 12946 Random number Max (100) : 39 Random number : 22934 Random number Max (100) : 48 Random number : 4690 Random number Max (100) : 52 Random number : 13196 Random number Max (100) : 65 Random number : 30390 Random number Max (100) : 87 Random number : 4327 Random number Max (100) : 77 Random number : 12456 Random number Max (100) : 17 Random number : 28438 33.3. Random() Function 262
- 3. Ring Documentation, Release 1.8 Random number Max (100) : 13 Random number : 30503 Random number Max (100) : 6 Random number : 31769 Random number Max (100) : 94 Random number : 8274 Random number Max (100) : 65 Random number : 14390 Random number Max (100) : 90 Random number : 28866 Random number Max (100) : 12 Random number : 24558 Random number Max (100) : 70 Random number : 29981 Random number Max (100) : 77 Random number : 12847 Random number Max (100) : 63 Random number : 6632 Random number Max (100) : 60 33.4 Unsigned() Function We can use unsigned numbers using the Unsigned() function. Syntax: Unsigned(nNum1,nNum2,cOperator) --> result of cOperator operation on nNum1,nNum2 Example: see oat_hash("hello") + nl # Jenkins hash function - https://en.wikipedia.org/wiki/Jenkins_hash_function func oat_hash cKey h = 0 for x in cKey h = unsigned(h,ascii(x),"+") h = unsigned(h,unsigned(h,10,"<<"),"+") r = unsigned(h,6,">>") h = unsigned(h, r,"^") next h = unsigned(h,unsigned(h,3,"<<"),"+") h = unsigned(h,unsigned(h,11,">>"),"^") h = unsigned(h,unsigned(h,15,"<<"),"+") return h Output: 3372029979.00 33.5 Decimals() Functions We can determine the decimals numbers count after the point in float/double numbers using the decimals() function. Syntax: 33.4. Unsigned() Function 263
- 4. Ring Documentation, Release 1.8 Decimals(nDecimalsCount) Example: x = 1.1234567890123 for d = 0 to 14 decimals(d) see x + nl next Output: 1 1.1 1.12 1.123 1.1235 1.12346 1.123457 1.1234568 1.12345679 1.123456789 1.1234567890 1.12345678901 1.123456789012 1.1234567890123 1.12345678901230 33.6 Using _ in numbers We can use _ between numbers digits. Example: x = 1_000_000 see type(x)+nl see x+1+nl Output: NUMBER 100000001 33.7 Using f after numbers We can use the ‘f’ letter after numbers. Example: x = 19.99f see type(x) + nl Output: NUMBER 33.6. Using _ in numbers 264
- 5. CHAPTER THIRTYFOUR FILES In this chapter we are going to learn about files functions. • Read() • Write() • Dir() • Rename() • Remove() • fopen() • fclose() • fflush() • freopen() • tempfile() • tempname() • fseek() • ftell() • rewind() • fgetpos() • fsetpos() • clearerr() • feof() • ferror() • perror() • fgetc() • fgets() • fputc() • fputs() • ungetc() • fread() 265
- 6. Ring Documentation, Release 1.8 • fwrite() • fexists() • Numbers and Bytes 34.1 Read() Function We can read the file content using the Read() function Syntax: Read(cFileName) ---> String contains the file content Example: see read("myfile.txt") The read function can read binary files too Example: see read("myapp.exe") 34.2 Write() Function We can write string to file using the Write() function The write function can write binary data to binary files. Syntax: Write(cFileName,cString) # write string cString to file cFileName Example: # copy file cFile = read("ring.exe") write("ring2.exe",cFile) 34.3 Dir() Function We can get the folder contents (files & sub folders) using the Dir() function. Syntax: Dir(cFolderPath) ---> List contains files & sub folders. This function returns a list and each list item is a list of two items • File/sub folder name • Type (0 = File , 1 = Folder/Directory) Example: 34.1. Read() Function 266
- 7. Ring Documentation, Release 1.8 see "Testing DIR() " + nl mylist = dir("C:myfolder") for x in mylist if x[2] see "Directory : " + x[1] + nl else see "File : " + x[1] + nl ok next see "Files count : " + len(mylist) 34.4 Rename() Function We can rename files using the Rename() function Syntax: Rename(cOldFileName,cNewFileName) Example: rename("file.txt","help.txt") 34.5 Remove() Function We can delete a file using the Remove() function Syntax: Remove(cFileName) Example: remove("test.txt") 34.6 Fopen() Function We can open a file using the Fopen() function Syntax: Fopen(cFileName,cMode) ---> File Handle Mode Description “r” Reading (The file must exist) “w” Writing (create empty file / overwrite) “a” Appends (create file if it doesn’t exist) “r+” update (reading/writing) “w+” Create empty file (reading/writing) “a+” reading & appending 34.4. Rename() Function 267
- 8. Ring Documentation, Release 1.8 34.7 Fclose() Function When we open a file using fopen() function, we can close it using the Fclose() function Syntax: Fclose(file handle) 34.8 Fflush() Function We can flushes the output buffer of a stream using the Fflush() function Syntax: Fflush(file handle) 34.9 Freopen() Function We can open another file using the same file handle and at the same time close the old file Syntax: Freopen(cFileName,cMode,file handle) ---> file handle Example: freopen("myprogoutput.txt","w+",stdout) see "welcome" + nl for x = 1 to 10 see x + nl next /* ** Read : https://en.wikipedia.org/wiki/Device_file#Device_files ** The next code is not portable, we can use iswindows() before ** using it and we can write special code for each operating system. */ freopen("CON","w",stdout) # For Microsoft Windows see "Done" + nl # print to stdout again Output: # Output to stdout Done # Output to file : myprogoutput.txt welcome 1 2 3 4 5 6 7 34.7. Fclose() Function 268
- 9. Ring Documentation, Release 1.8 8 9 10 34.10 Tempfile() Function The function Tempfile() creates a temp. file (binary). The file will be deleted automatically when the stream is closed Syntax: TempFile() ---> file handle 34.11 Tempname() Function We can generate temp. file name using the Tempname() function The generated name will be different from the name of any existing file Syntax: Tempname() ---> generated file name as string 34.12 Fseek() Function We can set the file position of the stream using the Fseek() function Syntax: Fseek(file handle, nOffset, nWhence) ---> zero if successful The next table presents the nWhence values Value Description 0 Beginning of file 1 Current position 2 End of file 34.13 Ftell() Function We can know the current file position of a stream using the Ftell() function Syntax: Ftell(file handle) ---> file position as number 34.10. Tempfile() Function 269
- 10. Ring Documentation, Release 1.8 34.14 Rewind() Function We can set the file position to the beginning of the file using the Rewind() function Syntax: Rewind(file handle) 34.15 Fgetpos() Function We can get handle to the current file position using the Fgetpos() function Syntax: Fgetpos(file handle) ---> position handle 34.16 Fsetpos() Function We can set the current file position using the Fgetpos() function Syntax: Fsetpos(file handle,position handle) 34.17 Clearerr() Function We can clear the EOF error and the error indicators of a stream using the clearerr() function Syntax: Clearerr(file handle) 34.18 Feof() Function We can test the end-of-file indicator using the Feof() function Syntax: Feof(file handle) ---> returns 1 if EOF and 0 if not 34.19 Ferror() Function We can test the error indicator of a given stream using the Ferror() function Syntax: Ferror(file handle) ---> returns 1 if error and 0 if not 34.14. Rewind() Function 270