Added examples 20-37

docs/sysutex/Makefile

@@ -32,7 +32,10 @@ endif
 
 .PHONY: all tex clean
 
-OBJECTS=ex1 ex2 ex3 ex4 ex5 ex6 ex7 ex8 ex9 ex10 ex11 ex12
+OBJECTS=ex1 ex2 ex3 ex4 ex5 ex6 ex7 ex8 ex9 ex10 ex11 ex12\
+        ex13 ex14 ex15 ex16 ex17 ex18 ex19 ex20 ex21 ex22 ex23 ex24\
+        ex25 ex26 ex27 ex28 ex29 ex30 ex31 ex32 ex33 ex34 ex35 ex36\
+        ex37
 
 TEXOBJECTS=$(addsuffix .tex, $(OBJECTS))
 

docs/sysutex/README

@@ -5,7 +5,6 @@ ex2.pp contains an example of the DateTimeToFileDate function.
 ex3.pp contains an example of the DateTimeToStr function.
 ex4.pp contains an example of the DateTimeToString function.
 ex5.pp contains an example of the DateTimeToSystemTime function.
-ex6.pp contains an example of the DateTimeToTimeStamp function.
 ex7.pp contains an example of the DateToStr function.
 exex8.pp contains an example of the DayOfWeek function.
 ex9.pp contains an example of the DecodeDate function.
@@ -20,3 +19,21 @@ ex16.pp contains an example of the IsLeapYear function.
 ex17.pp contains an example of the MSecsToTimeStamp function.
 ex18.pp contains an example of the Now function.
 ex19.pp contains an example of the StrToDate function.
+ex19.pp contains an example of the StrToDateTime function.
+ex21.pp contains an example of the StrToTime function.
+ex22.pp contains an example of the SystemTimeToDateTime function.
+ex23.pp contains an example of the Time function.
+ex24.pp contains an example of the TimeStampToDateTime function.
+ex25.pp contains an example of the TimeToStr function.
+ex26.pp contains an example of the CreateDir and RemoveDir function.
+ex27.pp contains an example of the DiskFree function.
+ex28.pp contains an example of the GetCurrentDir function.
+ex29.pp contains an example of the SetCurrentDir function.
+ex30.pp contains an example of the ChangeFileExt function.
+ex31.pp contains an example of the DeleteFile function.
+ex32.pp contains an example of the DoDirSeparators function.
+ex33.pp contains an example of the ExpandFileName function.
+ex34.pp contains an example of the ExtractFileName function.
+ex35.pp contains an example of the ExtractRelativePath function.
+ex36.pp contains an example of the FileAge function.
+ex37.pp contains an example of the FileCreate function.

docs/sysutex/ex20.pp

@@ -0,0 +1,20 @@
+Program Example20;
+
+{ This program demonstrates the StrToDateTime function }
+
+Uses sysutils;
+
+Procedure TestStr (S : String);
+
+begin
+  Writeln (S,' : ',DateTimeToStr(StrToDateTime(S)));
+end;
+
+Begin
+  
+  Writeln ('ShortDateFormat ',ShortDateFormat);
+  TestStr(DateTimeToStr(Now));
+  TestStr('05-05-1999 15:50');
+  TestStr('5-5 13:30');
+  TestStr('5 1:30PM');
+End.

docs/sysutex/ex21.pp

@@ -0,0 +1,18 @@
+Program Example21;
+
+{ This program demonstrates the StrToTime function }
+
+Uses sysutils;
+
+Procedure TestStr (S : String);
+
+begin
+  Writeln (S,' : ',TimeToStr(StrToTime(S)));
+end;
+
+Begin
+  teststr (TimeToStr(Time));
+  teststr ('12:00');
+  teststr ('15:30');
+  teststr ('3:30PM');
+End.

docs/sysutex/ex22.pp

@@ -0,0 +1,17 @@
+Program Example22;
+
+{ This program demonstrates the SystemTimeToDateTime function }
+
+Uses sysutils;
+
+Var ST : TSystemTime;
+
+Begin
+  DateTimeToSystemTime(Now,ST);
+  With St do
+    begin
+    Writeln ('Today is    ',year,'/',month,'/',Day);
+    Writeln ('The time is ',Hour,':',minute,':',Second,'.',MilliSecond);
+    end;
+  Writeln ('Converted : ',DateTimeToStr(SystemTimeToDateTime(ST)));
+End.

docs/sysutex/ex23.pp

@@ -0,0 +1,9 @@
+Program Example23;
+
+{ This program demonstrates the Time function }
+
+Uses sysutils;
+
+Begin
+  Writeln ('The time is : ',TimeToStr(Time));
+End.

docs/sysutex/ex24.pp

@@ -0,0 +1,19 @@
+Program Example24;
+
+{ This program demonstrates the TimeStampToDateTime function }
+
+Uses sysutils;
+
+Var TS : TTimeStamp;
+    DT : TDateTime;
+    
+Begin
+  TS:=DateTimeToTimeStamp (Now);
+  With TS do
+    begin
+    Writeln ('Now is ',time,' millisecond past midnight');
+    Writeln ('Today is ' ,Date,' days past 1/1/0001');
+    end;
+  DT:=TimeStampToDateTime(TS);
+  Writeln ('Together this is : ',DateTimeToStr(DT));
+End.

docs/sysutex/ex25.pp

@@ -0,0 +1,9 @@
+Program Example25;
+
+{ This program demonstrates the TimeToStr function }
+
+Uses sysutils;
+
+Begin
+  Writeln ('The current time is : ',TimeToStr(Time));
+End.

docs/sysutex/ex26.pp

@@ -0,0 +1,19 @@
+Program Example26;
+
+{ This program demonstrates the CreateDir and RemoveDir functions }
+{ Run this program twice in the same directory }
+
+Uses sysutils;
+
+Begin
+  If Not FileExists('NewDir') then
+    If Not CreateDir ('NewDir') Then
+      Writeln ('Failed to create directory !')
+    else
+      Writeln ('Created "NewDir" directory')
+  Else
+    If Not RemoveDir ('NewDir') Then
+      Writeln ('Failed to remove directory !')
+    else
+      Writeln ('Removed "NewDir" directory');
+End.

docs/sysutex/ex27.pp

@@ -0,0 +1,12 @@
+Program Example27;
+
+{ This program demonstrates the DiskFree function }
+
+Uses sysutils;
+
+Begin
+  Write ('Size of current disk       : ',DiskSize(0));
+  Writeln (' (= ',DiskSize(0) div 1024,'k)');
+  Write ('Free space of current disk : ',Diskfree(0));
+  Writeln (' (= ',Diskfree(0) div 1024,'k)');
+End.

docs/sysutex/ex28.pp

@@ -0,0 +1,9 @@
+Program Example28;
+
+{ This program demonstrates the GetCurrentDir function }
+
+Uses sysutils;
+
+Begin
+  Writeln ('Current Directory is : ',GetCurrentDir); 
+End.

docs/sysutex/ex29.pp

@@ -0,0 +1,12 @@
+Program Example29;
+
+{ This program demonstrates the SetCurrentDir function }
+
+Uses sysutils;
+
+Begin
+  If SetCurrentDir ('..') Then
+    Writeln ('Now in directory ',GetCurrentDir)
+  else 
+    Writeln ('Change directory to .. failed.');
+End.

docs/sysutex/ex30.pp

@@ -0,0 +1,19 @@
+Program Example30;
+
+{ This program demonstrates the ChangeFileExt function }
+
+Uses sysutils;
+
+Procedure testit (N,E : String);
+
+begin
+  Write ('Changing "',n,'" with extension "',e,'" : ');
+  Writeln (ChangeFileExt(N,E));
+end;
+
+Begin
+  Testit ('report.txt','.pas');
+  Testit ('file','.txt');
+  Testit ('/path/file.pas','.pp');
+  Testit ('/path/file.pp.org','.new');
+End.

docs/sysutex/ex31.pp

@@ -0,0 +1,18 @@
+Program Example31;
+
+{ This program demonstrates the DeleteFile function }
+
+Uses sysutils;
+
+Var
+  Line : String;
+  F,I : Longint;
+
+Begin
+  F:=FileCreate('test.txt');
+  Line:='Some string line.'#10;
+  For I:=1 to 10 do
+    FileWrite (F,Line[1],Length(Line));
+  FileClose(F);  
+  DeleteFile('test.txt');
+End.

docs/sysutex/ex32.pp

@@ -0,0 +1,21 @@
+Program Example32;
+
+{ This program demonstrates the DoDirSeparators function }
+{$H+}
+
+Uses sysutils;
+
+Procedure Testit (F : String);
+
+begin
+  Writeln ('Before : ',F);
+  DoDirSeparators (F);
+  Writeln ('After  : ',F);
+end;
+
+Begin
+  Testit (GetCurrentDir);
+  Testit ('c:\pp\bin\win32');
+  Testit ('/usr/lib/fpc');
+  Testit ('\usr\lib\fpc');
+End.

docs/sysutex/ex33.pp

@@ -0,0 +1,19 @@
+Program Example33;
+
+{ This program demonstrates the ExpandFileName function }
+
+Uses sysutils;
+
+Procedure Testit (F : String);
+
+begin
+  Writeln (F,' expands to : ',ExpandFileName(F));
+end;
+
+Begin
+  Testit('ex33.pp');
+  Testit(ParamStr(0));
+  Testit('/pp/bin/win32/ppc386');
+  Testit('\pp\bin\win32\ppc386');
+  Testit('.');
+End.

docs/sysutex/ex34.pp

@@ -0,0 +1,23 @@
+Program Example34;
+
+{ This program demonstrates the ExtractFileName function }
+{$H+}
+Uses sysutils;
+
+Procedure Testit(F : String);
+
+begin
+ Writeln ('FileName      : ',F);
+ Writeln ('Has Name      : ',ExtractFileName(F));
+ Writeln ('Has Path      : ',ExtractFilePath(F));
+ Writeln ('Has Extension : ',ExtractFileExt(F));
+ Writeln ('Has Directory : ',ExtractFileDir(F));
+ Writeln ('Has Drive     : ',ExtractFileDrive(F));
+end;
+
+Begin
+  Testit (Paramstr(0));
+  Testit ('/usr/local/bin/mysqld');
+  Testit ('c:\pp\bin\win32\ppc386.exe');
+  Testit ('/pp/bin/win32/ppc386.exe');
+End.

docs/sysutex/ex35.pp

@@ -0,0 +1,19 @@
+Program Example35;
+
+{ This program demonstrates the ExtractRelativePath function }
+
+Uses sysutils;
+
+Procedure Testit (FromDir,ToDir : String);
+
+begin
+  Write ('From "',FromDir,'" to "',ToDir,'" via "');
+  Writeln (ExtractRelativePath(FromDir,ToDir),'"');
+end;
+
+Begin
+ Testit ('/pp/src/compiler','/pp/bin/win32/ppc386');
+ Testit ('/pp/bin/win32/ppc386','/pp/src/compiler');
+ Testit ('e:/pp/bin/win32/ppc386','d:/pp/src/compiler');
+ Testit ('e:\pp\bin\win32\ppc386','d:\pp\src\compiler');
+End.

docs/sysutex/ex36.pp

@@ -0,0 +1,16 @@
+Program Example36;
+
+{ This program demonstrates the FileAge function }
+
+Uses sysutils;
+
+Var S : TDateTime;
+    fa : Longint;
+Begin
+  fa:=FileAge('ex36.pp');
+  If Fa<>-1 then
+    begin
+    S:=FileDateTodateTime(fa);
+    Writeln ('I''m from ',DateTimeToStr(S))
+    end;
+End.

docs/sysutex/ex37.pp

@@ -0,0 +1,31 @@
+Program Example37;
+
+{ This program demonstrates the FileCreate function }
+
+Uses sysutils;
+
+Var I,J,F : Longint;
+
+Begin
+  F:=FileCreate ('test.dat');
+  If F=-1 then 
+    Halt(1);
+  For I:=0 to 100 do
+    FileWrite(F,I,SizeOf(i));
+  FileClose(f);
+  F:=FileOpen ('test.dat',fmOpenRead);
+  For I:=0 to 100 do
+    begin
+    FileRead (F,J,SizeOF(J));
+    If J<>I then
+      Writeln ('Mismatch at file position ',I)
+    end;
+  FileSeek(F,0,0);
+  Randomize;
+  Repeat
+    FileSeek(F,Random(100)*4,0);
+    FileRead (F,J,SizeOf(J));
+    Writeln ('Random read : ',j);
+  Until J>80;
+  FileClose(F);
+End.

docs/sysutils.tex

@@ -330,7 +330,7 @@ Function DateTimeToTimeStamp(DateTime: TDateTime): TTimeStamp;
 None.
 \SeeAlso
 \seef{DateTimeToFileDate}, \seef{SystemTimeToDateTime},
-\seef{DateTimeToSystemTime}
+\seep{DateTimeToSystemTime}
 \end{function}
 
 \latex{\inputlisting{sysutex/ex6.pp}}
@@ -511,7 +511,7 @@ None.
 Function IsLeapYear(Year: Word): boolean;
 \Description
 \var{IsLeapYear} returns \var{True} if \var{Year} is a leap year,
-\var{False} otherwise
+\var{False} otherwise.
 \Errors
 None.
 \SeeAlso
@@ -527,6 +527,9 @@ Function MSecsToTimeStamp(MSecs: Comp): TTimeStamp;
 \Description
 \var{MSecsTiTimeStamp} converts the given number of milliseconds to
 a \var{TTimeStamp} date/time notation.
+
+Use \var{TTimeStamp} variables if you need to keep very precise track of
+time.
 \Errors
 None.
 \SeeAlso
@@ -566,183 +569,362 @@ The order of the digits (y/m/d, m/d/y, d/m/y) is determined from the
 \var{ShortDateFormat} variable.
 \Errors
 On error (e.g. an invalid date or invalid character), 
-a \var{EConvertError} exception is raised.
+an \var{EConvertError} exception is raised.
 \SeeAlso
 \seef{StrToTime}, \seef{DateToStr}n \seef{TimeToStr}.
 \end{function}
 
- \latex{\inputlisting{sysutex/ex19.pp}}
+\latex{\inputlisting{sysutex/ex19.pp}}
 \html{\input{sysutex/ex19.tex}}
 
 \begin{function}{StrToDateTime}
 \Declaration
 Function StrToDateTime(const S: string): TDateTime;
 \Description
+\var{StrToDateTime} converts the string \var{S} to a \var{TDateTime} date 
+and time value. The Date must consist of 1 to three digits, separated by the 
+\var{DateSeparator} character. If two numbers are given, they
+are supposed to form the day and month of the current year. If only 
+one number is given, it is supposed to represent the day of the 
+current month. (This is \em{not} supported in Delphi)
 
+The order of the digits (y/m/d, m/d/y, d/m/y) is determined from the 
+\var{ShortDateFormat} variable.
 \Errors
+On error (e.g. an invalid date or invalid character), 
+an \var{EConvertError} exception is raised.
 \SeeAlso
+\seef{StrToDate}, \seef{StrToTime}, \seef{DateTimeToStr}
 \end{function}
 
+\latex{\inputlisting{sysutex/ex20.pp}}
+\html{\input{sysutex/ex20.tex}}
  
 \begin{function}{StrToTime}
 \Declaration
 Function StrToTime(const S: string): TDateTime;
 \Description
+\var{StrToTime} converts the string \var{S} to a \var{TDateTime} time 
+value. The time must consist of 1 to 4 digits, separated by the 
+\var{TimeSeparator} character. If two numbers are given, they
+are supposed to form the hour and minutes. 
 \Errors
+On error (e.g. an invalid date or invalid character), 
+an \var{EConvertError} exception is raised.
 \SeeAlso
+\seef{StrToDate}, \seef{StrToDateTime}, \seef{TimeToStr}
 \end{function}
 
- 
+\latex{\inputlisting{sysutex/ex21.pp}}
+\html{\input{sysutex/ex21.tex}}
+
 \begin{function}{SystemTimeToDateTime}
 \Declaration
 Function SystemTimeToDateTime(const SystemTime: TSystemTime): TDateTime;
 \Description
+\var{SystemTimeToDateTime} converts a \var{TSystemTime} record to a
+\var{TDateTime} style date/time indication.
 \Errors
+None.
 \SeeAlso
+\seep{DateTimeToSystemTime}
 \end{function}
 
- 
+\latex{\inputlisting{sysutex/ex22.pp}}
+\html{\input{sysutex/ex22.tex}}
+
 \begin{function}{Time}
 \Declaration
 Function Time: TDateTime;
 \Description
+\var{Time} returns the current time in \var{TDateTime} format. The date
+part of the \var{TDateTimeValue} is set to zero.
 \Errors
+None.
 \SeeAlso
+\seef{Now}, \seef{Date}
 \end{function}
 
+
+\latex{\inputlisting{sysutex/ex23.pp}}
+\html{\input{sysutex/ex23.tex}}
  
 \begin{function}{TimeStampToDateTime}
 \Declaration
 Function TimeStampToDateTime(const TimeStamp: TTimeStamp): TDateTime;
 \Description
+\var{TimeStampToDateTime} converts \var{TimeStamp} to a \var{TDateTime}
+format variable. It is the inverse operation of \seef{DateTimeToTimeStamp}.
 \Errors
+None.
 \SeeAlso
+\seef{DateTimeToTimeStamp}, \seef{TimeStampToMSecs}
 \end{function}
 
- 
+\latex{\inputlisting{sysutex/ex24.pp}}
+\html{\input{sysutex/ex24.tex}}
+
 \begin{function}{TimeStampToMSecs}
 \Declaration
 Function TimeStampToMSecs(const TimeStamp: TTimeStamp): comp;
 \Description
+\var{TimeStampToMSecs} converts {TimeStamp} to the number of seconds
+since \var{1/1/0001}.
+
+Use \var{TTimeStamp} variables if you need to keep very precise track of
+time.
 \Errors
+None.
 \SeeAlso
+\seef{MSecsToTimeStamp}, \seef{TimeStampToDateTime}
 \end{function}
 
- 
+For an example, see \seef{MSecsToTimeStamp}.
+
 \begin{function}{TimeToStr}
 \Declaration
 Function TimeToStr(Time: TDateTime): string;
 \Description
+\var{TimeToStr} converts the time in \var{Time} to a string. It uses
+the \var{ShortTimeFormat} variable to see what formatting needs to be
+applied. It is therefor entirely equivalent to a
+\var{FormatDateTime('t',Time)} call.
 \Errors
+None.
 \SeeAlso
 \end{function}
 
+\latex{\inputlisting{sysutex/ex25.pp}}
+\html{\input{sysutex/ex25.tex}}
  
 
 \section{Disk functions}
 
+\begin{functionl}{AddDisk (Linux only)}{AddDisk}
+\Declaration
+Function AddDisk (Const PAth : String) : Longint;
+\Description
+On Linux  both the \seef{Diskfree} and \seef{Disksize} functions need a 
+file on the specified drive, since is required for the statfs system call.
+
+These filenames are set in drivestr[0..26], and the first 4 have been 
+preset to :
+\begin{description}
+\item[Disk 0]  \var{'.'} default drive - hence current directory is used.
+\item[Disk 1]  \var{'/fd0/.'} floppy drive 1.
+\item[Disk 2]  \var{'/fd1/.'} floppy drive 2.
+\item[Disk 3]  \var{'/'} \file{C:} equivalent of DOS is the root partition.
+\end{description}
+Drives 4..26 can be set by your own applications with the \var{AddDisk} call.
+
+The \var{AddDisk} call adds \var{Path} to the names of drive files, and
+returns the number of the disk that corresponds to this drive. If you
+add more than 21 drives, the count is wrapped to 4.
+\Errors
+None. 
+\SeeAlso
+\seef{DiskFree}, \seef{DiskSize}
+\end{functionl}
+
 \begin{function}{CreateDir}
 \Declaration
 Function CreateDir(Const NewDir : String) : Boolean;
 \Description
+\var{CreateDir} creates a new directory with name \var{NewDir}.
+If the directory doesn't contain an absolute path, then the directory is
+created below the current working directory.
+
+The function returns \var{True} if the directory was successfully 
+created, \var{False} otherwise.
 \Errors
+In case of an error, the function returns \var{False}.
 \SeeAlso
+\seef{RemoveDir}
 \end{function}
 
+\latex{\inputlisting{sysutex/ex26.pp}}
+\html{\input{sysutex/ex26.tex}}
  
 \begin{function}{DiskFree}
 \Declaration
 Function DiskFree(Drive : Byte) : Longint;
 \Description
+\var{DiskFree} returns the free space (in bytes) on disk \var{Drive}.
+Drive is the number of the disk drive: 
+\begin{description}
+\item[0] for the current drive.
+\item[1] for the first floppy drive.
+\item[2] for the second floppy drive.
+\item[3] for the first hard-disk parttion.
+\item[4-26] for all other drives and partitions.
+\end{description}
+
+{\em Remark} Under \linux, and Unix in general, the concept of disk is
+different than the \dos one, since the filesystem is seen as one big
+directory tree. For this reason, the \var{DiskFree} and \seef{DiskSize}
+functions must be mimicked using filenames that reside on the partitions.
+For more information, see \seef{AddDisk}
 \Errors
+On error, \var{-1} is returned.
 \SeeAlso
+\seef{DiskSize}, \seef{AddDisk}
 \end{function}
 
+\latex{\inputlisting{sysutex/ex27.pp}}
+\html{\input{sysutex/ex27.tex}}
  
 \begin{function}{DiskSize}
 \Declaration
 Function DiskSize(Drive : Byte) : Longint;
 \Description
+\var{DiskSize} returns the size (in bytes) of disk \var{Drive}.
+Drive is the number of the disk drive: 
+\begin{description}
+\item[0] for the current drive.
+\item[1] for the first floppy drive.
+\item[2] for the second floppy drive.
+\item[3] for the first hard-disk parttion.
+\item[4-26] for all other drives and partitions.
+\end{description}
+
+{\em Remark} Under \linux, and Unix in general, the concept of disk is
+different than the \dos one, since the filesystem is seen as one big
+directory tree. For this reason, the \seef{DiskFree} and \var{DiskSize}
+functions must be mimicked using filenames that reside on the partitions.
+For more information, see \seef{AddDisk}
 \Errors
+On error, \var{-1} is returned.
 \SeeAlso
+\seef{DiskFree}, \seef{AddDisk}
 \end{function}
 
+For an example, see \seef{DiskFree}.
  
 \begin{function}{GetCurrentDir}
 \Declaration
 Function GetCurrentDir : String;
 \Description
+\var{GetCurrentDir} returns the current working directory.
 \Errors
+None.
 \SeeAlso
+\seef{SetCurrentDir}, \seef{DiskFree}, \seef{DiskSize}
 \end{function}
 
+\latex{\inputlisting{sysutex/ex28.pp}}
+\html{\input{sysutex/ex28.tex}}
  
 \begin{function}{RemoveDir}
 \Declaration
 Function RemoveDir(Const Dir : String) : Boolean;
 \Description
+\var{RemoveDir} removes directory \var{Dir} from the disk.
+If the directory is not absolue, it is appended to the current working 
+directory.
 \Errors
+In case of error (e.g. the directory isn't empty) the function returns 
+\var{False}. If successful, \var{True} is returned.
 \SeeAlso
 \end{function}
 
+For an example, see \seef{CreateDir}.
  
 \begin{function}{SetCurrentDir}
 \Declaration
 Function SetCurrentDir(Const NewDir : String) : Boolean;
 \Description
+\var{SetCurrentDir} sets the current working directory of your program
+to \var{NewDir}. It returns \var{True} if the function was successfull,
+\var{False} otherwise.
 \Errors
+In case of error, \var{False} is returned.
 \SeeAlso
+\seef{GetCurrentDir}
 \end{function}
 
- 
-
+\latex{\inputlisting{sysutex/ex29.pp}}
+\html{\input{sysutex/ex29.tex}}
 
 \section{File handling functions}
 
-      
-  
 \begin{function}{ChangeFileExt}
 \Declaration
 Function ChangeFileExt(const FileName, Extension: string): string;
 \Description
+\var{ChangeFileExt} changes the file extension in \var{FileName} to
+\var{Extension}. 
+The extension \var{Extension} includes the starting \var{.} (dot).
+The previous extension of \var{FileName} are all characters after the
+last \var{.}, the \var{.} character included.
+
+If \var{FileName} doesn't have an extension, \var{Extension} is just
+appended.
 \Errors
+None.
 \SeeAlso
+\seef{ExtractFileName}, \seef{ExtractFilePath}, \seef{ExpandFileName}
 \end{function}
 
- 
+
 \begin{function}{DeleteFile}
 \Declaration
 Function DeleteFile(Const FileName : String) : Boolean;
 \Description
+\var{DeleteFile} deletes file \var{FileName} from disk. The function
+returns \var{True} if the file was successfully removed, \var{False}
+otherwise.
 \Errors
+On error, \var{False} is returned.
 \SeeAlso
+\seef{CreateFile}, \seef{FileExists}
 \end{function}
 
+\latex{\inputlisting{sysutex/ex31.pp}}
+\html{\input{sysutex/ex31.tex}}
  
 \begin{procedure}{DoDirSeparators}
 \Declaration
 Procedure DoDirSeparators(Var FileName : String);
 \Description
+This function replaces all directory separators \var{'\' and '/'}
+to the directory separator character for the current system.
 \Errors
+None.
 \SeeAlso
+\seef{ExtractFileName}, \seef{ExtractFilePath}
 \end{procedure}
 
- 
+\latex{\inputlisting{sysutex/ex32.pp}}
+\html{\input{sysutex/ex32.tex}}
+
 \begin{function}{ExpandFileName}
 \Declaration
 Function ExpandFileName(Const FileName : string): String;
 \Description
+\var{ExpandFileName} expands the filename to an absolute filename.
+It changes all directory separator characters to the one appropriate for the
+system first.
 \Errors
+None.
 \SeeAlso
+\seef{ExtractFileName}, \seef{ExtractFilePath}, \seef{ExtractFileDir},
+\seef{ExtractFileDrive}, \seef{ExtractFileExt}, \seef{ExtractRelativePath}
 \end{function}
 
+\latex{\inputlisting{sysutex/ex33.pp}}
+\html{\input{sysutex/ex33.tex}}
+
  
 \begin{function}{ExpandUNCFileName}
 \Declaration
 Function ExpandUNCFileName(Const FileName : string): String;
 \Description
+\var{ExpandUNCFileName} runs \seef{ExpandFileName} on \var{FileName}
+and then attempts to replace the driveletter by the name of a shared disk.
 \Errors
 \SeeAlso
+\seef{ExtractFileName}, \seef{ExtractFilePath}, \seef{ExtractFileDir},
+\seef{ExtractFileDrive}, \seef{ExtractFileExt}, \seef{ExtractRelativePath}
 \end{function}
 
  
@@ -750,71 +932,134 @@ Function ExpandUNCFileName(Const FileName : string): String;
 \Declaration
 Function ExtractFileDir(Const FileName : string): string;
 \Description
+\var{ExtractFileDir} returns only the directory part of \var{FileName},
+not including a driveletter. The directory name has NO ending directory
+separator, in difference with \seef{ExtractFilePath}. 
 \Errors
+None.
 \SeeAlso
+\seef{ExtractFileName}, \seef{ExtractFilePath}, \seef{ExtractFileDir},
+\seef{ExtractFileDrive}, \seef{ExtractFileExt}, \seef{ExtractRelativePath}
 \end{function}
 
- 
+\latex{\inputlisting{sysutex/ex34.pp}}
+\html{\input{sysutex/ex34.tex}}
+
 \begin{function}{ExtractFileDrive}
 \Declaration
 Function ExtractFileDrive(const FileName: string): string;
 \Description
+\var{Extract}
 \Errors
 \SeeAlso
+\seef{ExtractFileName}, \seef{ExtractFilePath}, \seef{ExtractFileDir},
+\seef{ExtractFileDrive}, \seef{ExtractFileExt}, \seef{ExtractRelativePath}
 \end{function}
 
+For an example, see \seef{ExtractFileDir}.
  
 \begin{function}{ExtractFileExt}
 \Declaration
 Function ExtractFileExt(const FileName: string): string; 
 \Description
+\var{ExtractFileExt} returns the extension (including the 
+\var{.}(dot) character) of \var{FileName}.
 \Errors
+None.
 \SeeAlso
+\seef{ExtractFileName}, \seef{ExtractFilePath}, \seef{ExtractFileDir},
+\seef{ExtractFileDrive}, \seef{ExtractFileExt}, \seef{ExtractRelativePath}
 \end{function}
 
+For an example, see \seef{ExtractFileDir}.
  
 \begin{function}{ExtractFileName}
 \Declaration
 Function ExtractFileName(const FileName: string): string;
 \Description
+\var{ExtractFileName} returns the filename part from \var{FileName}.
+The filename consists of all characters after the last directory separator
+character ('/' or '\') or drive letter. 
+
+The full filename can always be reconstucted by concatenating the result
+of \seef{ExtractFilePath} and \var{ExtractFileName}.
 \Errors
+None.
 \SeeAlso
+\seef{ExtractFileName}, \seef{ExtractFilePath}, \seef{ExtractFileDir},
+\seef{ExtractFileDrive}, \seef{ExtractFileExt},\seef{ExtractRelativePath}
 \end{function}
 
+For an example, see \seef{ExtractFileDir}.
  
 \begin{function}{ExtractFilePath}
 \Declaration
 Function ExtractFilePath(const FileName: string): string;
 \Description
+\var{ExtractFilePath} returns the path part (including driveletter) from 
+\var{FileName}. The path consists of all characters before the last 
+directory separator character ('/' or '\'), including the directory
+separator itself. 
+In case there is only a drive letter, that will be returned.
+
+The full filename can always be reconstucted by concatenating the result
+of \var{ExtractFilePath} and \seef{ExtractFileName}.
 \Errors
+None.
 \SeeAlso
+\seef{ExtractFileName}, \seef{ExtractFilePath}, \seef{ExtractFileDir},
+\seef{ExtractFileDrive}, \seef{ExtractFileExt}, \seef{ExtractRelativePath}
 \end{function}
 
+For an example, see \seef{ExtractFileDir}.
  
-\begin{function}{ExtractRelativepath}
+\begin{function}{ExtractRelativePath}
 \Declaration
-Function ExtractRelativepath(Const BaseName,DestNAme : String): String;
+Function ExtractRelativePath(Const BaseName,DestNAme : String): String;
 \Description
+\var{ExtractRelativePath} constructs a relative path to go from
+\var{BaseName} to \var{DestName}. If \var{DestName} is on another drive
+(Not on Linux) then the whole \var{Destname} is returned.
+
+{\em Note:} This function does not exist in the Delphi unit.
 \Errors
+None.
 \SeeAlso
+\seef{ExtractFileName}, \seef{ExtractFilePath}, \seef{ExtractFileDir},
+\seef{ExtractFileDrive}, \seef{ExtractFileExt},
 \end{function}
 
- 
+\latex{\inputlisting{sysutex/ex35.pp}}
+\html{\input{sysutex/ex35.tex}}
+
 \begin{function}{FileAge}
 \Declaration
 Function FileAge(Const FileName : String): Longint;
 \Description
+\var{FileAge} returns the last modification time of file \var{FileName}.
+The FileDate format can be transformed to \var{TDateTime} format with the
+\seef{FileDateToDateTime} function.
 \Errors
+In case of errors, \var{-1} is returned.
 \SeeAlso
+\seef{FileDateToDateTime}, \seef{FileExists}, \seef{FileGetAttr}
 \end{function}
 
+\latex{\inputlisting{sysutex/ex36.pp}}
+\html{\input{sysutex/ex36.tex}}
+
  
 \begin{procedure}{FileClose}
 \Declaration
 Procedure FileClose(Handle : Longint);
 \Description
+\var{FileClose} closes the file handle \var{Handle}. After this call,
+attempting to read or write from the handle will result in an error.
 \Errors
+None.
 \SeeAlso
+\seef{FileCreate}, \seef{FileWrite}, \seef{FileOpen}, \seef{FileRead},
+\seef{FileTruncate}, \seef{FileSeek}
 \end{procedure}
 
  
@@ -822,8 +1067,18 @@ Procedure FileClose(Handle : Longint);
 \Declaration
 Function FileCreate(Const FileName : String) : Longint;
 \Description
+\var{FileCreate} creates a new file with name \var{FileName} on the disk and
+returns a file handle which can be used to read or write from the file with
+the \seef{FileRead} and \seef{FileWrite} functions.
+
+If a file with name \var{FileName} already existed on the disk, it is
+overwritten.
 \Errors
+If an error occurs (e.g. disk full or non-existent path), the function
+returns \var{-1}.
 \SeeAlso
+\seef{FileClose}, \seef{FileWrite}, \seef{FileOpen}, \seef{FileRead},
+\seef{FileTruncate}, \seef{FileSeek}
 \end{function}
 
  
@@ -831,8 +1086,12 @@ Function FileCreate(Const FileName : String) : Longint;
 \Declaration
 Function FileExists(Const FileName : String) : Boolean;
 \Description
+\var{FileExists} returns \var{True} if a file with name \var{FileName}
+exists on the disk, \var{False} otherwise.
 \Errors
+None.
 \SeeAlso
+\seef{FileAge}, \seef{FileGetAttr}, \seef{FileSetAttr}
 \end{function}
 
  
@@ -840,11 +1099,25 @@ Function FileExists(Const FileName : String) : Boolean;
 \Declaration
 Function FileGetAttr(Const FileName : String) : Longint;
 \Description
+\var{FileGetAttr} returns the attribute settings of file 
+\var{FileName}. The attribute is a \var{OR}-ed combination
+of the following constants: 
+\begin{description}
+\item[faReadOnly] The file is read-only.
+\item[faHidden] The file is hidden. (On \linux, this means that the filename
+starts with a dot)
+\item[faSysFile] The file is a system file (On \linux, this means that the
+file is a character, block or FIFO file).
+\item[faVolumeId] Volume Label. Not possible under \linux.
+\item[faDirectory] File is a directory.
+\item[faArchive] file is an archive. Not possible on \linux.
+\end{description}
 \Errors
+In case of error, -1 is returned.
 \SeeAlso
+\seef{FileSetAttr}, \seef{FileAge}, \seef{FileGetDate}.
 \end{function}
 
- 
 \begin{function}{FileGetDate}
 \Declaration
 Function FileGetDate(Handle : Longint) : Longint;
@@ -860,6 +1133,8 @@ Function FileOpen(Const FileName : string; Mode : Integer) : Longint;
 \Description
 \Errors
 \SeeAlso
+\seef{FileClose}, \seef{FileWrite}, \seef{FileCreate}, \seef{FileRead},
+\seef{FileTruncate}, \seef{FileSeek}
 \end{function}
 
  
@@ -869,6 +1144,8 @@ Function FileRead(Handle : Longint; Var Buffer; Count : longint) : Longint;
 \Description
 \Errors
 \SeeAlso
+\seef{FileClose}, \seef{FileWrite}, \seef{FileCreate}, \seef{FileOpen},
+\seef{FileTruncate}, \seef{FileSeek}
 \end{function}
 
  
@@ -887,6 +1164,8 @@ Function FileSeek(Handle,Offset,Origin : Longint) : Longint;
 \Description
 \Errors
 \SeeAlso
+\seef{FileClose}, \seef{FileWrite}, \seef{FileCreate}, \seef{FileOpen}
+\seef{FileRead}, \seef{FileTruncate}
 \end{function}
 
  
@@ -914,6 +1193,8 @@ Function FileTruncate(Handle,Size: Longint) : boolean;
 \Description
 \Errors
 \SeeAlso
+\seef{FileClose}, \seef{FileWrite}, \seef{FileCreate}, \seef{FileOpen}
+\seef{FileRead}, \seef{FileSeek}
 \end{function}
 
  
@@ -923,6 +1204,8 @@ Function FileWrite(Handle : Longint; Var Buffer; Count : Longint) : Longint;
 \Description
 \Errors
 \SeeAlso
+\seef{FileClose}, \seef{FileCreate}, \seef{FileOpen}
+\seef{FileRead}, \seef{FileTruncate}, \seef{FileSeek}
 \end{function}