Changes the list of currently blocked signals. The behaviour of the call depends on How :

SIG_BLOCK

The set of blocked signals is the union of the current set and the nset argument.

SIG_UNBLOCK

The signals in nset are removed from the set of currently blocked signals.

SIG_SETMASK

The list of blocked signals is set so nset.

If oset is non-nil, then the old set is stored in it.

fpMkFifo creates named a named pipe in the filesystem, with name Path and mode Mode.

The function returns zero if the command was succesful, and nonzero if it failed.

fpChmod sets the Mode bits of the file in Path to Mode. Mode can be specified by 'or'-ing the following values:

S_ISUID

Set user ID on execution.

S_ISGID

Set Group ID on execution.

S_ISVTX

Set sticky bit.

S_IRUSR

Read by owner.

S_IWUSR

Write by owner.

S_IXUSR

Execute by owner.

S_IRGRP

Read by group.

S_IWGRP

Write by group.

S_IXGRP

Execute by group.

S_IROTH

Read by others.

S_IWOTH

Write by others.

S_IXOTH

Execute by others.

S_IRWXO

Read, write, execute by others.

S_IRWXG

Read, write, execute by groups.

S_IRWXU

Read, write, execute by user.

If the function is successful, zero is returned. A nonzero return value indicates an error.

fpChown sets the User ID and Group ID of the file in Path to Owner,Group.

The function returns zero if the call was succesfull, a nonzero return value indicates an error.

FpPipe creates a pipe, i.e. two file objects, one for input, one for output. The filehandles are returned in the array fildes. The input handle is in the 0-th element of the array, the output handle is in the 1-st element.

The function returns zero if everything went succesfully, a nonzero return value indicates an error.

FpDup returns a file descriptor that is a duplicate of the file descriptor fildes.

The second and third forms make NewFile an exact copy of OldFile, after having flushed the buffer of OldFile in case it is a Text file or untyped file. Due to the buffering mechanism of Pascal, these calls do not have the same functionality as the dup call in C. The internal Pascal buffers are not the same after this call, but when the buffers are flushed (e.g. after output), the output is sent to the same file. Doing an lseek will, however, work as in C, i.e. doing a lseek will change the fileposition in both files.

The function returns a negative value in case of an error, a positive value is a file handle, and indicates succes.

Makes fildes2 or NewFile an exact copy of fildes or OldFile, after having flushed the buffer of OldFile in the case of text or untyped files.

NewFile can be an assigned file. If newfile was open, it is closed first. Due to the buffering mechanism of Pascal, this has not the same functionality as the dup2 call in C. The internal Pascal buffers are not the same after this call, but when the buffers are flushed (e.g. after output), the output is sent to the same file. Doing an lseek will, however, work as in C, i.e. doing a lseek will change the fileposition in both files.

The function returns zero if succesful, a nonzero return value means the call failed.

fpTimes stores the execution time of the current process and child processes in buffer.

The return value (on linux) is the number of clock ticks since boot time. On error, -1 is returned, and extended error information can be retrieved with .

FpAlarm schedules an alarm signal to be delivered to your process in Seconds seconds. When Seconds seconds have elapsed, the system will send a SIGALRM signal to the current process. If Seconds is zero, then no new alarm will be set. Whatever the value of Seconds, any previous alarm is cancelled.

The function returns the number of seconds till the previously scheduled alarm was due to be delivered, or zero if there was none. A negative value indicates an error.

FpPause puts the process to sleep and waits until the application receives a signal. If a signal handler is installed for the received sigal, the handler will be called and after that pause will return control to the process.

For an example, see .

FpSleep suspends the process till a time period as specified in seconds has passed, then the function returns. If the call was interrupted (e.g. by some signal) then the function may return earlier, and the return value is the remaining time till the end of the intended period.

If the function returns without error, the return value is zero.

fpSetUID sets the user ID of the current process. This call will only work if it is executed as root, or the program is setuid root.

On success, zero is returned, on error -1 is returned.

fpSetUID sets the group ID of the current process. This call will only work if it is executed as root, or the program is setgid root.

On success, zero is returned, on error -1 is returned.

FpGetgroups returns up to gidsetsize groups in GroupList

If the function is successful, then number of groups that were stored is returned. On error, -1 is returned.

Read/set a file's attributes. Fildes a valid file descriptor. Cmd speciefies what to do, and is one of the following:

F_GetFd

Read the close_on_exec flag. If the low-order bit is 0, then the file will remain open across execve calls.

F_GetFl

Read the descriptor's flags.

F_GetOwn

Get the Process ID of the owner of a socket.

F_SetFd

Set the close_on_exec flag of fildes. (only the least siginificant bit is used).

F_GetLk

Return the flock record that prevents this process from obtaining the lock, or set the l_type field of the lock of there is no obstruction. Arg is the flock record.

F_SetLk

Set the lock or clear it (depending on l_type in the flock structure). if the lock is held by another process, an error occurs.

F_GetLkw

Same as for F_Setlk, but wait until the lock is released.

F_SetOwn

Set the Process or process group that owns a socket.

The function returns 0 if successful, -1 otherwise.

fpgetCWD returns the current working directory of the running process. It is returned in Path, which points to a memory location of at least siz bytes.

If the function is succesful, a pointer to Path is returned, or a string with the result. On error Nil or an empty string are returned.

fpWaitPid waits for a child process with process ID Pid to exit. The value of Pid can be one of the following:

Pid < -1

Causes fpWaitPid to wait for any child process whose process group ID equals the absolute value of pid.

Pid = -1

Causes fpWaitPid to wait for any child process.

Pid = 0

Causes fpWaitPid to wait for any child process whose process group ID equals the one of the calling process.

Pid > 0

Causes fpWaitPid to wait for the child whose process ID equals the value of Pid.

The Options parameter can be used to specify further how fpWaitPid behaves:

WNOHANG

Causes fpWaitpid to return immediately if no child hasexited.

WUNTRACED

Causes fpWaitPid to return also for children which are stopped, but whose status has not yet been reported.

__WCLONE

Causes fpWaitPid also to wait for threads created by the call.

The exit status of the process that caused fpWaitPID is reported in stat_loc or Status.

Upon return, it returns the process id of the process that exited, 0 if no process exited, or -1 in case of failure.

For an example, see .

fpWait suspends the current process and waits for any child to exit or stop due to a signal. It reports the exit status of the exited child in stat_loc.

The return value of the function is the process ID of the child that exited, or -1 on error.

FpExit exits the currently running process, and report Status as the exit status.

fpKill sends a signal Sig to a process or process group. If Pid>0 then the signal is sent to Pid, if it equals -1, then the signal is sent to all processes except process 1. If Pid<-1 then the signal is sent to process group -Pid.

The return value is zero, except in case three, where the return value is the number of processes to which the signal was sent.

Uname gets the name and configuration of the current linux kernel, and returns it in the name record.

On success, 0 is returned, on error, -1 is returned.

FpReadDir reads the next entry in the directory pointed to by dirp. It returns a pdirent pointer to a record describing the entry. If the next entry can't be read, Nil is returned.

For an example, see .

FpCloseDir closes the directory pointed to by dirp. It returns zero if the directory was closed succesfully, -1 otherwise.

For an example, see .

fpChDir sets the current working directory to Path.

It returns zero if the call was succesful, -1 on error.

FpOpen opens a file in Path with flags flags and mode Mode One of the following:

O_RdOnly

File is opened Read-only

O_WrOnly

File is opened Write-only

O_RdWr

File is opened Read-Write

The flags may beOR-ed with one of the following constants:

O_Creat

File is created if it doesn't exist.

O_Excl

If the file is opened with O_Creat and it already exists, the call wil fail.

O_NoCtty

If the file is a terminal device, it will NOT become the process' controlling terminal.

O_Trunc

If the file exists, it will be truncated.

O_Append

the file is opened in append mode. Before each write, the file pointer is positioned at the end of the file.

O_NonBlock

The file is opened in non-blocking mode. No operation on the file descriptor will cause the calling process to wait till.

O_NDelay

Idem as O_NonBlock

O_Sync

The file is opened for synchronous IO. Any write operation on the file will not return untill the data is physically written to disk.

O_NoFollow

if the file is a symbolic link, the open fails. (linux 2.1.126 and higher only)

O_Directory

if the file is not a directory, the open fails. (linux 2.1.126 and higher only)

Path can be of type PChar or String. The optional mode argument specifies the permissions to set when opening the file. This is modified by the umask setting. The real permissions are Mode and not umask. The return value of the function is the filedescriptor, or a negative value if there was an error.

FpMkDir creates a new directory Path, and sets the new directory's mode to Mode. Path can be an absolute path or a relative path. Note that only the last element of the directory will be created, higher level directories must already exist, and must be writeable by the current user.

On succes, 0 is returned. if the function fails, -1 is returned.

FpUnLink decreases the link count on file Path. Path can be of type AnsiString or PChar. If the link count is zero, the file is removed from the disk.

The function returns zero if the call was succesfull, a nonzero value indicates failure.

For an example, see .

FpRmdir removes the directory Path from the system. The directory must be empty for this call to succeed, and the user must have the necessary permissions in the parent directory. Only the last component of the directory is removed, i.e. higher-lying directories are not removed.

On success, zero is returned. A nonzero return value indicates failure.

FpRename renames the file Old to NewPath. NewPath can be in a different directory than Old, but it cannot be on another partition (device). Any existing file on the new location will be replaced.

If the operation fails, then the Old file will be preserved.

The function returns zero on succes, a nonzero value indicates failure.

FpFStat gets information about the file specified in one of the following:

Fd

a valid file descriptor.

F

an opened text file or untyped file.

and stores it in Info, which is of type . The function returns zero if the call was succesfull, a nonzero return value indicates failure.

FpFStat gets information about the file specified in Path, and stores it in Info, which is of type . The function returns zero if the call was succesfull, a nonzero return value indicates failure.

FpAccess tests user's access rights on the specified file. Mode is a mask existing of one or more of the following:

R_OK

User has read rights.

W_OK

User has write rights.

X_OK

User has execute rights.

F_OK

File exists.

The test is done with the real user ID, instead of the effective user ID. If the user has the requested rights, zero is returned. If access is denied, or an error occurred, a nonzero value is returned.

FpClose closes a file with file descriptor Fd. The function returns zero if the file was closed successfully, a nonzero return value indicates an error.

For an example, see .

FpdRead reads at most nbytes bytes from the file descriptor fd, and stores them in buf.

The function returns the number of bytes actually read, or -1 if an error occurred. No checking on the length of buf is done.

FpWrite writes at most nbytes bytes from buf to file descriptor fd.

The function returns the number of bytes actually written, or -1 if an error occurred.

FpLSeek sets the current fileposition of file fd to Offset, starting from Whence, which can be one of the following:

Seek_Set

Offset is the absolute position in the file.

Seek_Cur

Offset is relative to the current position.

Seek_end

Offset is relative to the end of the file.

The function returns the new fileposition, or -1 of an error occurred.

For an example, see .

FpTime returns the number of seconds since 00:00:00 GMT, january 1, 1970. it is adjusted to the local time zone, but not to DST. The result is also stored in tloc, if it is specified.

FpFTruncate sets the length of a file in fd on flength bytes, where flength must be less than or equal to the current length of the file in fd.

The function returns zero if the call was successful, a nonzero return value indicates that an error occurred.

FPSigaction changes the action to take upon receipt of a signal. Act and Oact are pointers to a record. Sig specifies the signal, and can be any signal except SIGKILL or SIGSTOP.

If Act is non-nil, then the new action for signal Sig is taken from it. If OAct is non-nil, the old action is stored there. Sa_Handler may be SIG_DFL for the default action or SIG_IGN to ignore the signal. Sa_Mask Specifies which signals should be ignord during the execution of the signal handler. Sa_Flags Speciefies a series of flags which modify the behaviour of the signal handler. You can 'or' none or more of the following :

SA_NOCLDSTOP

If sig is SIGCHLD do not receive notification when child processes stop.

SA_ONESHOT or SA_RESETHAND

Restore the signal action to the default state once the signal handler has been called.

SA_RESTART

For compatibility with BSD signals.

SA_NOMASK or SA_NODEFER

Do not prevent the signal from being received from within its own signal handler.

FpSelect checks one of the file descriptors in the FDSets to see if its status changed.

readfds, writefds and exceptfds are pointers to arrays of 256 bits. If you want a file descriptor to be checked, you set the corresponding element in the array to 1. The other elements in the array must be set to zero. Three arrays are passed : The entries in readfds are checked to see if characters become available for reading. The entries in writefds are checked to see if it is OK to write to them, while entries in exceptfds are cheked to see if an exception occorred on them.

You can use the functions , , or to manipulate the individual elements of a set.

The pointers can be Nil.

N is the largest index of a nonzero entry plus 1. (= the largest file-descriptor + 1).

TimeOut can be used to set a time limit. If TimeOut can be two types :

1. TimeOut is of type ptimeval and contains a zero time, the call returns immediately. If TimeOut is Nil, the kernel will wait forever, or until a status changed.
2. TimeOut is of type cint. If it is -1, this has the same effect as a Timeout of type PTime which is Nil. Otherwise, TimeOut contains a time in milliseconds.

When the TimeOut is reached, or one of the file descriptors has changed, the Select call returns. On return, it will have modified the entries in the array which have actually changed, and it returns the number of entries that have been changed. If the timout was reached, and no decsriptor changed, zero is returned; The arrays of indexes are undefined after that. On error, -1 is returned.

The variant with the text file will execute the FpSelect call on the file descriptor associated with the text file T

FpNanoSleep suspends the process till a time period as specified in req has passed. Then the function returns. If the call was interrupted (e.g. by some signal) then the function may return earlier, and rem will contain the remaining time till the end of the intended period. In this case the return value will be -1, and LinuxError will be set to EINTR

If the function returns without error, the return value is zero.

FPGetEnv returns the value of the environment variable in Name. If the variable is not defined, nil is returned. The value of the environment variable may be the empty string. A PChar is returned to accomodate for strings longer than 255 bytes, TERMCAP and LS_COLORS, for instance.

FpUtime sets the access and modification times of the file specified in Path. the times record contains 2 fields, actime, and modtime, both of type time_t (commonly a longint). They should be filled with an epoch-like time, specifying, respectively, the last access time, and the last modification time. For some filesystem (most notably, FAT), these times are the same.

The function returns zero on success, a nonzero return value indicates failure.

FPSignal installs a new signal handler (specified by Handler) for signal SigNum.

This call has a subset of the functionality provided by the call. The return value for FpSignal is the old signal handler, or nil on error.

FpFD_Set sets file descriptor fdno in filedescriptor set nset.

For an example, see .

FpFD_Clr clears file descriptor fdno in filedescriptor set nset.

For an example, see .

FpFD_ZERO clears all the filedescriptors in the file descriptor set nset.

For an example, see .

FpFD_Set Checks whether file descriptor fdNo in filedescriptor set fds is set. It returns zero if the descriptor is not set, 1 if it is set. If the number of the filedescriptor it wrong, -1 is returned.

For an example, see .

fpseterrno sets the extended information on the latest error. It is called by all functions that communicate with the kernel or C library.

Unless a direct kernel call is performed, there should never be any need to call this function.

FpMMap maps or unmaps files or devices into memory. The different arguments determine what and how the file is mapped:

adr

Address where to mmap the device. This address is a hint, and may not be followed.

len

Size (in bytes) of area to be mapped.

prot

Protection of mapped memory. This is a OR-ed combination of the following constants:

PROT_EXEC

The memory can be executed.

PROT_READ

The memory can be read.

PROT_WRITE

The memory can be written.

PROT_NONE

The memory can not be accessed.

flags

Contains some options for the mmap call. It is an OR-ed combination of the following constants:

MAP_FIXED

Do not map at another address than the given address. If the address cannot be used, MMap will fail.

MAP_SHARED

Share this map with other processes that map this object.

MAP_PRIVATE

Create a private map with copy-on-write semantics.

MAP_ANONYMOUS

fd does not have to be a file descriptor.

One of the options MAP_SHARED and MAP_PRIVATE must be present, but not both at the same time.

fd

File descriptor from which to map.

off

Offset to be used in file descriptor fd.

The function returns a pointer to the mapped memory, or a -1 in case of en error.

FpMUnMap unmaps the memory block of size Len, pointed to by Adr, which was previously allocated with .

The function returns True if successful, False otherwise.

For an example, see .

Nice adds -N to the priority of the running process. The lower the priority numerically, the less the process is favored. Only the superuser can specify a negative N, i.e. increase the rate at which the process is run.

If the function is succesful, zero is returned. On error, a nonzero value is returned.

GetPriority returns the priority with which a process is running. Which process(es) is determined by the Which and Who variables. Which can be one of the pre-defined Prio_Process, Prio_PGrp, Prio_User, in which case Who is the process ID, Process group ID or User ID, respectively.

For an example, see .

fpSetPriority sets the priority with which a process is running. Which process(es) is determined by the Which and Who variables. Which can be one of the pre-defined constants:

Prio_Process

Who is interpreted as process ID

Prio_PGrp

Who is interpreted as process group ID

Prio_User

Who is interpreted as user ID

Prio is a value in the range -20 to 20.

For an example, see .

The function returns zero on success, -1 on failure

SymLink makes NewName point to the file in OldName, which doesn't necessarily exist. The two files DO NOT have the same inode number. This is known as a 'soft' link.

The permissions of the link are irrelevant, as they are not used when following the link. Ownership of the file is only checked in case of removal or renaming of the link.

The function returns zero if the call was succesful, a nonzero value if the call failed.

FpReadLink returns the file the symbolic link name is pointing to. The first form of this function accepts a buffer linkname of length 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.