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+ Added mising functions, part I

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michael 2000-05-21 19:07:07 +00:00
parent b97ef5dd00
commit 114652d0b1
1 changed files with 237 additions and 14 deletions
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docs/linux.tex
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@ -49,18 +49,66 @@ TGlob = record
\end{verbatim}
The following types are used in the signal-processing procedures.
\begin{verbatim}
{$Packrecords 1}
tfpreg = record
significand: array[0..3] of word;
exponent: word;
end;
pfpstate = ^tfpstate;
tfpstate = record
cw, sw, tag, ipoff, cssel, dataoff, datasel: cardinal;
st: array[0..7] of tfpreg;
status: cardinal;
end;
PSigContextRec = ^SigContextRec;
SigContextRec = record
gs, __gsh: word;
fs, __fsh: word;
es, __esh: word;
ds, __dsh: word;
edi: cardinal;
esi: cardinal;
ebp: cardinal;
esp: cardinal;
ebx: cardinal;
edx: cardinal;
ecx: cardinal;
eax: cardinal;
trapno: cardinal;
err: cardinal;
eip: cardinal;
cs, __csh: word;
eflags: cardinal;
esp_at_signal: cardinal;
ss, __ssh: word;
fpstate: pfpstate;
oldmask: cardinal;
cr2: cardinal;
end;
\end{verbatim}
The above records contain information about the processor state and process
state at the moment a signal is sent to your program.
The records below are used in catching signals.
\begin{verbatim}
TSigAction = procedure(Sig: Longint; SigContext: SigContextRec);cdecl;
SignalHandler = Procedure ( Sig : Integer);cdecl;
PSignalHandler = SignalHandler;
SignalRestorer = Procedure;cdecl;
PSignalrestorer = SignalRestorer;
SigActionRec = Record
Sa_Handler : Signalhandler;
Sa_Mask : Longint;
Sa_flags : Integer;
Sa_Restorer : SignalRestorer;
SigActionRec = packed record
Handler : record
case byte of
0: (Sh: SignalHandler);
1: (Sa: TSigAction);
end;
Sa_Mask : SigSet;
Sa_Flags : Longint;
Sa_restorer : SignalRestorer; { Obsolete - Don't use }
end;
PSigActionRec = ^SigActionRec;
PSigActionRec = ^SigActionRec;
\end{verbatim}
Stat is used to store information about a file. It is defined in the
syscalls unit.
@ -516,7 +564,6 @@ errors:
\item[sys\_enfile] The system file table is full.
\end{description}
Other errors include the ones by the fork and exec programs
\SeeAlso
\seef{AssignPipe}, \seep{POpen},\seem{pipe}{2}
\end{function}
@ -665,6 +712,55 @@ symbolic link, i.e. a symbolic link, whose expansion points to itself.
\FPCexample{ex23}
\begin{function}{Clone}
\Declaration
TCloneFunc=function(args:pointer):longint;cdecl;
Clone(func:TCloneFunc;sp:pointer;flags:longint;args:pointer):longint;
\Description
Clone creates a child process which is a copy of the parent process, just
like \seef{Fork} does. In difference with \var{Fork}, however, the child
process shares some parts of it's execution context with its parent, so it
is suitable for the implementation of threads: many instances of a program
that share the same memory.
When the child process is created, it starts executing the function
\var{Func}, and passes it \var{Args}. The return value of \var{Func} is
either the explicit return value of the function, or the exit code of
the child process.
The \var{sp} pointer points to the memory reserved as stack space for the
child process. This address should be the top of the memory block to be used
as stack.
The \var{Flags} determine the behaviour of the \var{Clone} call. The low
byte of the Flags contains the number of the signal that will be sent to
the parent when the child dies.
This may be bitwise OR'ed with the following constants:
\begin{description}
\item[CLONE\_VM] Parent and child share the same memory space, including
memory (un)mapped with subsequent \var{mmap} calls.
\item[CLONE\_FS] Parent and child have the same view of the filesystem;
the \var{chroot}, \var{chdir} and \var{umask} calls affect both processes.
\item[CLONE\_FILES] the file descriptor table of parent and child is shared.
\item[CLONE\_SIGHAND] the parent and child share the same table of signal
handlers. The signal masks are different, though.
\item[CLONE\_PID] PArent and child have the same process ID.
\end{description}
Clone returns the process ID in the parent process, and -1 if an error
occurred.
\Errors
On error, -1 is returned to the parent, and no child is created.
\begin{description}
\item [sys\_eagain] Too many processes are running.
\item [sys\_enomem] Not enough memory to create child process.
\end{description}
\SeeAlso
\seef{Fork}, \seem{clone}{2}
\end{function}
\FPCexample{ex14}
\begin{function}{CloseDir}
\Declaration
Function CloseDir (p:pdir) : integer;
@ -1396,12 +1492,54 @@ On error, -1 is returned to the parent, and no child is created.
\begin{description}
\item [sys\_eagain] Not enough memory to create child process.
\end{description}
\SeeAlso
\seep{Execve}, \seem{fork}{2}
\seep{Execve}, \seef{Clone}, \seem{fork}{2}
\end{function}
\begin{function}{FRename}
\Declaration
Function FReName (OldName,NewName : Pchar) : Boolean;
Function FReName (OldName,NewName : String) : Boolean;
\Description
\var{FRename} renames the file \var{OldName} to \var{NewName}. \var{NewName}
can be in a different directory than \var{OldName}, but it cannot be on
another partition (device). Any existing file on the new location will be replaced.
If the operation fails, then the \var{OldName} file will be preserved.
The function returns \var{True} on succes, \var{False} on failure.
\Errors
On error, errors are reported in \var{LinuxError}. Possible errors include:
\begin{description}
\item[sys\_eisdir] \var{NewName} exists and is a directory, but \var{OldName}
is not a directory.
\item[sys\_exdev] \var{NewName} and \var{OldName} are on different devices.
\item[sys\_enotempty or sys\_eexist] \var{NewName} is an existing, non-empty
directory.
\item[sys\_ebusy] \var{OldName} or \var{NewName} is a directory and is in
use by another process.
\item[sys\_einval] \var{NewName} is part of \var{OldName}.
\item[sys\_emlink] \var{OldPath} or \var{NewPath} already have tha maximum
amount of links pointing to them.
\item[sys\_enotdir] part of \var{OldName} or \var{NewName} is not
directory.
\item[sys\_efault] For the \var{pchar} case: One of the pointers points to
an invalid address.
\item[sys\_eaccess] access is denied when attempting to move the file.
\item[sys\_enametoolong] Either \var{OldName} or \var{NewName} is too long.
\item[sys\_enoent] a directory component in \var{OldName} or \var{NewName}
didn't exist.
\item[sys\_enomem] not enough kernel memory.
\item[sys\_erofs] \var{NewName} or \var{OldName} is on a read-only file
system.
\item[sys\_eloop] too many symbolic links were encountered trying to expand
\var{OldName} or \var{NewName}
\item[sys\_enospc] the filesystem has no room for the new directory entry.
\end{description}
\SeeAlso
\seef{UnLink}
\end{function}
\FPCexample{ex14}
\begin{procedure}{GetDate}
\Declaration
@ -1557,7 +1695,7 @@ procedure GetLocalTimezone(timer:longint);
initializes the \var{TZSeconds} variable, which is used to correct the epoch time
to local time.
You should never call this function directly. It is called by the
There should never be any need to call this function directly. It is called by the
initialization routines of the Linux unit.
\SeeAlso
\seef{GetTimezoneFile}, \seep{ReadTimezoneFile}
@ -2055,6 +2193,20 @@ Function MkFifo (PathName: String; Mode : Longint) : Boolean;
\seep{POpen}, \seef{MkFifo}, \seem{mkfifo}{4}
\end{function}
\begin{function}{MMap}
\Declaration
Function MMap(const m:tmmapargs):longint;
\Description
\var{MMap} maps or unmaps files or devices into memory. The different fields
of the argument \var{m} determine what and how the \var{mmap} maps this:
\begin{description}
\item[address] Address where to mmap the device. This address is a hint
\item[size]
\item[prot]
\item[flags]
\item[fd]
\item[offset]
\end{description}
\begin{procedure}{Nice}
\Declaration
Procedure Nice ( N : Integer);
@ -2168,6 +2320,40 @@ Errors are returned in LinuxError.
For an example, see \seef{OpenDir}.
\begin{function}{ReadLink}
\Declaration
Function ReadLink(name,linkname:pchar;maxlen:longint):longint;
Function ReadLink(name:pathstr):pathstr;
\Description
\var{ReadLink} returns the file the symbolic link \var{name} is pointing
to. The first form of this function accepts a buffer \var{linkname} of
length \var{maxlen} where the filename will be stored. It returns the
actual number of characters stored in the buffer.
The second form of the function returns simply the name of the file.
\Errors
On error, the first form of the function returns -1; the second one returns
an empty string. \var{LinuxError} is set to report errors:
\begin{description}
\item[SYS\_ENOTDIR] A part of the path in \var{Name} is not a directory.
\item[SYS\_EINVAL] maxlen is not positive, or the file is not a symbolic link.
\item[SYS\_ENAMETOOLONG] A pathname, or a component of a pathname, was too
long.
\item[SYS\_ENOENT] the link \var{name} does not exist.
\item[SYS\_EACCES] No permission to search a directory in the path
\item[SYS\_ELOOP] Too many symbolic links were encountered in trans­
lating the pathname.
\item[SYS\_EIO] An I/O error occurred while reading from the file
system.
\item[SYS\_EFAULT] The buffer is not part of the the process's memory space.
\item[SYS\_ENOMEM] Not enough kernel memory was available.
\end{description}
\SeeAlso
\seef{SymLink}
\end{function}
\FPCexample{ex62}
\begin{procedure}{ReadTimezoneFile}
\Declaration
procedure ReadTimezoneFile(fn:string);
@ -2402,6 +2588,19 @@ the range of the process.
\seem{Sigprocmask}{2}
\end{procedure}
\begin{procedure}{SigRaise}
\Declaration
Procedure SigRaise(Sig:integer);
\Description
\var{SigRaise} sends a \var{Sig} signal to the current process.
\Errors
None.
\SeeAlso
\seef{Kill}, \seef{GetPid}
\end{procedure}
\FPCexample{ex65}
\begin{procedure}{SigSuspend}
\Declaration
Procedure SigSuspend (Mask : SigSet);
@ -2469,13 +2668,37 @@ symbolic link, i.e. a symbolic link, whose expansion points to itself.
\item[sys\_enospc] The device containing \var{NewPath} has no room for anothe
entry.
\end{description}
\SeeAlso
\seef{Link}, \seef{UnLink}, \seem{Symlink}{2}
\seef{Link}, \seef{UnLink}, \seef{ReadLink}, \seem{Symlink}{2}
\end{function}
\FPCexample{ex22}
\begin{function}{SysInfo}
\Declaration
Function SysInfo(var Info:TSysinfo):Boolean;
\Description
\var{SysInfo} returns system information in \var{Info}. Returned information
in \var{Info} includes:
\begin{description}
\item[uptime] Number of seconds since boot.
\item[loads] 1, 5 and 15 minute load averages.
\item[totalram] total amount of main memory.
\item[freeram] amount of free memory.
\item[sharedram] amount of shared memory
\item[bufferram] amount of memory used by buffers.
\item[totalswap] total amount of swapspace.
\item[freeswap] amount of free swapspace.
\item[procs] number of current processes.
\end{description}
\Errors
None.
\SeeAlso
\seep{Uname}
\end{function}
\FPCexample{ex64}
\begin{function}{TCDrain}
\Declaration
Function TCDrain (Fd:longint) : Boolean;