The Ring programming language version 1.5.4 book - Part 26 of 185
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This document discusses various file and system functions in Ring including: - Rewind(), Fgetpos(), Fsetpos(), Clearerr(), Feof(), Ferror(), Perror(), Fgetc(), Fgets(), Fputc(), Fputs(), Ungetc(), Fread(), Fwrite(), and Fexists() functions for file handling - System(), SystemCmd(), SysGet(), IsMSDOS(), IsWindows(), IsWindows64(), IsUnix(), IsMacOSX(), IsLinux(), IsFreeBSD(), IsAndroid(), and Windowsnl() functions for system/OS information and commands - Examples of getting command line arguments, active source file name, and previous source file name
![Ring Documentation, Release 1.5.4
IsLinux() --> 0
IsFreeBSD() --> 0
IsAndroid() --> 0
32.12 Windowsnl() Function
We can get the windows new line string using the Windowsnl() function.
Syntax:
WindowsNL() ---> Returns a string contains CR+LF = CHAR(13) + CHAR(10)
Example:
cStr = read("input.txt")
if iswindows()
cStr = substr(cStr,windowsnl(),nl)
ok
aList = str2list(cStr)
# to do - list items processing using "for in"
cStr = list2str(aList)
if iswindows()
cStr = substr(cStr,nl,windowsnl())
ok
write("ouput.txt",cStr)
32.13 Get Command Line Arguments
We can get the command line arguments passed to the ring script using the sysargv variable.
The sysargv variable is a list contains the command line parameters.
Example
see copy("=",30) + nl
see "Command Line Parameters" + nl
see "Size : " + len(sysargv) + nl
see sysargv
see copy("=",30) + nl
if len(sysargv) < 4 return ok
nStart = sysargv[3]
nEnd = sysargv[4]
for x = nStart to nEnd
see x + nl
next
Output
b:mahmoudappsring>ring testssyspara.ring 1 10
==============================
Command Line Parameters
32.12. Windowsnl() Function 233](https://image.slidesharecdn.com/251ringfayedringdoc1-180426033358/85/The-Ring-programming-language-version-1-5-4-book-Part-26-of-185-9-320.jpg)
![Ring Documentation, Release 1.5.4
Size : 4
ring
testssyspara.ring
1
10
==============================
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10
32.14 Get Active Source File Name
We can get the active source file name (*.ring) using the filename() function
Syntax:
filename() ---> String contains the active source file name.
Example:
see "Active Source File Name : " + filename() + nl
Output:
Active Source File Name : testsfilename.ring
Example:
if sysargv[2] = filename()
see "I'm the main program file!" + nl
# we can run tests here!
else
see "I'm a sub file in a program" + nl
ok
32.15 PrevFileName() Function
Using the PrevFileName() function we can get the previous active source file name.
The previous file would be the file of the caller function, Or the file of the function that we called before calling
PrevFileName().
Syntax:
prevfilename() ---> String contains the previous source file name.
Example:
The next function in stdlib.ring uses the PrevFileName() to know if the file of the caller function is the main source
file of the program or not.
32.14. Get Active Source File Name 234](https://image.slidesharecdn.com/251ringfayedringdoc1-180426033358/85/The-Ring-programming-language-version-1-5-4-book-Part-26-of-185-10-320.jpg)
The Ring programming language version 1.5.4 book - Part 26 of 185
- 1. Ring Documentation, Release 1.5.4 31.14 Rewind() Function We can set the file position to the beginning of the file using the Rewind() function Syntax: Rewind(file handle) 31.15 Fgetpos() Function We can get handle to the current file position using the Fgetpos() function Syntax: Fgetpos(file handle) ---> position handle 31.16 Fsetpos() Function We can set the current file position using the Fgetpos() function Syntax: Fsetpos(file handle,position handle) 31.17 Clearerr() Function We can clear the EOF error and the error indicators of a stream using the clearerr() function Syntax: Clearerr(file handle) 31.18 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 31.19 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 31.14. Rewind() Function 225
- 2. Ring Documentation, Release 1.5.4 31.20 Perror() Function We can print error message to the stderr using the Perror() function Syntax: Perror(cErrorMessage) 31.21 Fgetc() Function We can get the next character from the stream using the Fgetc() function Syntax: Fgetc(file handle) ---> returns character or EOF 31.22 Fgets() Function We can read new line from the stream using the Fgets() function Syntax: Fgets(file handle,nSize) ---> string The function stop when nSize characters are read, new line character is read or EOF. 31.23 Fputc() Function We can write a character to the stream using the Fputc() function Syntax: Fputc(file handle,cChar) 31.24 Fputs() Function We can write a string to the stream using the Fputs() function Syntax: Fputs(file handle,cString) 31.25 Ungetc() Function We can push a character to the stream using the Ungetc() function The character will be available for the next read Syntax: 31.20. Perror() Function 226
- 3. Ring Documentation, Release 1.5.4 Ungetc(file handle,character) 31.26 Fread() Function We can read data from a stream using the Fread() function Syntax: Fread(file handle,nSize) 31.27 Fwrite() Function We can write data to a stream using the Fwrite() function Syntax: Fwrite(file handle,cString) 31.28 Fexists() Function We can check if a file exists using the Fexists() function Syntax: Fexists(cFileName) ---> returns 1 if the file exists Example: see fexists("b:mahmoudappsringring.exe") + nl + fexists("b:mahmoudappsringring2.exe") + nl Output: 1 0 31.29 Example The next program test some of the file functions See "testing file functions" + nl See "open file" + nl fp = fopen(exefolder() + "../tests/scripts/s65.ring","r") See "reopen" + nl fp = freopen(exefolder() + "../tests/scripts/s78.ring","r",fp) See "close file" + nl fclose(fp) see "temp file" + nl 31.26. Fread() Function 227
- 4. Ring Documentation, Release 1.5.4 fp = tempfile() fclose(fp) see "temp name" + nl see tempname() + nl remove(exefolder() + "../tests/scripts/mytest2.txt") write(exefolder() + "../tests/scripts/tests1.txt","hello") rename(exefolder() + "../tests/scripts/test1.txt",exefolder() + "../tests/scripts/mytests2.txt") see "print file" + nl fp = fopen(exefolder() + "../samples/fromdoc/filefuncs.ring","r") r = fgetc(fp) while isstring(r) see r r = fgetc(fp) end fclose(fp) see nl+"print line from the file" + nl fp = fopen(exefolder() + "../samples/fromdoc/filefuncs.ring","r") r = fgets(fp,33) see r + nl fclose(fp) fp = fopen(exefolder() + "../tests/scripts/test78.txt","w+") fseek(fp,0,2) # goto end of file fputc(fp,"t") fputc(fp,"e") fputc(fp,"s") fputc(fp,"t") fputs(fp,"tests2") fclose(fp) see "print file" + nl see read(exefolder() + "../tests/scripts/test78.txt") fp = fopen(exefolder() + "../tests/scripts/test78.txt","r") see "testing ungetc() " + nl for x = 1 to 3 r = fgetc(fp) see r + nl ungetc(fp,r) next fclose(fp) see "testing fread() " + nl fp = fopen(exefilename(),"rb") r = fread(fp,100) see r + nl fclose(fp) see "testing fwrite() " + nl fp = fopen(exefolder() + "../tests/scripts/test1.txt","wb") fwrite(fp,r) fclose(fp) The next example print part of the content of a binary file 31.29. Example 228
- 5. Ring Documentation, Release 1.5.4 see "Testing: fread()" +" FileName: "+ exefilename() +nl +nl fp = fopen(exefilename(),"rb") r = fread(fp,800) for n =1 to len(r) if isprint(substr(r, n, 1)) see substr(r, n, 1) else see "." ok ### 80 char per line if n % 80 = 0 see nl ok next fclose(fp) 31.30 Numbers and Bytes The next functions to convert between Numbers and Bytes. • Int2Bytes() • Float2Bytes() • Double2Bytes() • Bytes2Int() • Bytes2Float() • Bytes2Double() Example: see "Test Int2Bytes() and Bytes2Int() - Value : 77" + nl r = Int2Bytes(77) see "Int Size : " + len(r) + nl see r + nl see Bytes2Int(r) + nl see "Test Float2Bytes() and Bytes2Float() - Value 77.12" + nl r = Float2Bytes(77.12) see "Float Size : " + len(r) + nl see r + nl see Bytes2Float(r) + nl see "Test Double2Bytes() and Bytes2Double() - Value 9999977.12345" + nl r = Double2Bytes(9999977.12345) see "Double Size : " + len(r) + nl see r + nl decimals(5) see Bytes2Double(r) + nl 31.30. Numbers and Bytes 229
- 6. CHAPTER THIRTYTWO SYSTEM FUNCTIONS In this chapter we are going to learn about the system functions • System() • SystemCmd() • SysGet() • IsMSDOS() • IsWindows() • IsWindows64() • IsUnix() • IsMacOSX() • IsLinux() • IsFreeBSD() • IsAndroid() • Windowsnl() • Get Command Line Arguments • Get Active Source File Name • CurrentDir() • ExeFileName() • ChDir() • ExeFolder() • Version() • Shutdown() 32.1 System() Function We can execute system commands using the system() function Syntax: System(cCommand) 230
- 7. Ring Documentation, Release 1.5.4 Example: System("myapp.exe") # Run myapp.exe System("ls") # print list of files 32.2 SysGet() Function We can get environment variables using the Get() function Syntax: SysGet(cVariable) Example: see sysget("path") # print system path information 32.3 IsMSDOS() Function We can check if the operating system is MSDOS or not using the IsMSDOS() function Syntax: IsMSDOS() ---> Returns 1 if the operating system is MS-DOS, Returns 0 if it's not 32.4 IsWindows() Function We can check if the operating system is Windows or not using the IsWindows() function Syntax: IsWindows() ---> Returns 1 if the operating system is Windows, Returns 0 if it's not 32.5 IsWindows64() Function We can check if the operating system is Windows 64bit or not using the IsWindows64() function Syntax: IsWindows64() ---> Returns 1 if the operating system is Windows64, Returns 0 if it's not 32.6 IsUnix() Function We can check if the operating system is Unix or not using the IsUnix() function Syntax: IsUnix() ---> Returns 1 if the operating system is Unix, Returns 0 if it's not 32.2. SysGet() Function 231
- 8. Ring Documentation, Release 1.5.4 32.7 IsMacOSX() Function We can check if the operating system is Mac OS X or not using the IsMacOSX() function Syntax: IsMacOSX() ---> Returns 1 if the operating system is Mac OS X, Returns 0 if it's not 32.8 IsLinux() Function We can check if the operating system is Linux or not using the IsLinux() function Syntax: IsLinux() ---> Returns 1 if the operating system is Linux, Returns 0 if it's not 32.9 IsFreeBSD() Function We can check if the operating system is FreeBSD or not using the IsFreeBSD() function Syntax: IsFreeBSD() ---> Returns 1 if the operating system is FreeBSD, Returns 0 if it's not 32.10 IsAndroid() Function We can check if the operating system is Android or not using the IsAndroid() function Syntax: IsAndroid() ---> Returns 1 if the operating system is Android, Returns 0 if it's not 32.11 Example see "IsMSDOS() --> " + ismsdos() + nl see "IsWindows() --> " + iswindows() + nl see "IsWindows64() --> " + iswindows64() + nl see "IsUnix() --> " + isunix() + nl see "IsMacOSX() --> " + ismacosx() + nl see "IsLinux() --> " + islinux() + nl see "IsFreeBSD() --> " + isfreebsd() + nl see "IsAndroid() --> " + isandroid() + nl Output: IsMSDOS() --> 0 IsWindows() --> 1 IsWindows64() --> 0 IsUnix() --> 0 IsMacOSX() --> 0 32.7. IsMacOSX() Function 232
- 9. Ring Documentation, Release 1.5.4 IsLinux() --> 0 IsFreeBSD() --> 0 IsAndroid() --> 0 32.12 Windowsnl() Function We can get the windows new line string using the Windowsnl() function. Syntax: WindowsNL() ---> Returns a string contains CR+LF = CHAR(13) + CHAR(10) Example: cStr = read("input.txt") if iswindows() cStr = substr(cStr,windowsnl(),nl) ok aList = str2list(cStr) # to do - list items processing using "for in" cStr = list2str(aList) if iswindows() cStr = substr(cStr,nl,windowsnl()) ok write("ouput.txt",cStr) 32.13 Get Command Line Arguments We can get the command line arguments passed to the ring script using the sysargv variable. The sysargv variable is a list contains the command line parameters. Example see copy("=",30) + nl see "Command Line Parameters" + nl see "Size : " + len(sysargv) + nl see sysargv see copy("=",30) + nl if len(sysargv) < 4 return ok nStart = sysargv[3] nEnd = sysargv[4] for x = nStart to nEnd see x + nl next Output b:mahmoudappsring>ring testssyspara.ring 1 10 ============================== Command Line Parameters 32.12. Windowsnl() Function 233
- 10. Ring Documentation, Release 1.5.4 Size : 4 ring testssyspara.ring 1 10 ============================== 1 2 3 4 5 6 7 8 9 10 32.14 Get Active Source File Name We can get the active source file name (*.ring) using the filename() function Syntax: filename() ---> String contains the active source file name. Example: see "Active Source File Name : " + filename() + nl Output: Active Source File Name : testsfilename.ring Example: if sysargv[2] = filename() see "I'm the main program file!" + nl # we can run tests here! else see "I'm a sub file in a program" + nl ok 32.15 PrevFileName() Function Using the PrevFileName() function we can get the previous active source file name. The previous file would be the file of the caller function, Or the file of the function that we called before calling PrevFileName(). Syntax: prevfilename() ---> String contains the previous source file name. Example: The next function in stdlib.ring uses the PrevFileName() to know if the file of the caller function is the main source file of the program or not. 32.14. Get Active Source File Name 234