  
  [1X3 [33X[0;0YFunctions directly available from the C library[133X[101X
  
  [33X[0;0YThe  following  functions  from  the  C  library  are  made available as [5XGAP[105X
  functions:[133X
  
  [33X[0;0Y[10Xaccept[110X,  [10Xbind[110X,  [10Xchdir[110X,  [10Xchmod[110X,  [10Xchown[110X, [10Xclose[110X, [10Xclosedir[110X, [10Xconnect[110X, [10Xcreat[110X, [10Xdup[110X,
  [10Xdup2[110X,  [10Xexecv[110X,  [10Xexecve[110X,  [10Xexecvp[110X,  [10Xexit[110X,  [10Xfchmod[110X,  [10Xfchown[110X, [10Xfcntl[110X, [10Xfork[110X, [10Xfstat[110X,
  [10Xgethostbyname[110X,   [10Xgethostname[110X,   [10Xgetpid[110X,  [10Xgetppid[110X,  [10Xgetsockname[110X,  [10Xgetsockopt[110X,
  [10Xgettimeofday[110X,  [10Xgmtime[110X,  [10Xkill[110X, [10Xlchown[110X, [10Xlink[110X, [10Xlisten[110X, [10Xlocaltime[110X, [10Xlseek[110X, [10Xlstat[110X,
  [10Xmkdir[110X,  [10Xmkfifo[110X,  [10Xmknod[110X,  [10Xopen[110X, [10Xopendir[110X, [10Xpipe[110X, [10Xread[110X, [10Xreaddir[110X, [10Xreadlink[110X, [10Xrecv[110X,
  [10Xrecvfrom[110X,   [10Xrename[110X,   [10Xrewinddir[110X,   [10Xrmdir[110X,  [10Xseekdir[110X,  [10Xselect[110X,  [10Xsend[110X,  [10Xsendto[110X,
  [10Xsetsockopt[110X, [10Xsocket[110X, [10Xstat[110X, [10Xsymlink[110X, [10Xtelldir[110X, [10Xunlink[110X, [10Xwrite[110X.[133X
  
  [33X[0;0YUse the [10Xman[110X command in your shell to get information about these functions.[133X
  
  [33X[0;0YFor  each  of  these  functions there is a corresponding [5XGAP[105X global function
  with  the  prefix  [10XIO_[110X  before  its  name. Apart from minor differences (see
  below) they take exactly the same arguments as their C counterparts. Strings
  must  be  specified  as  [5XGAP[105X strings and integers as [5XGAP[105X immediate integers.
  Return values are in general the same as for the C counterparts. However, an
  error  condition  is  indicated  by the value [10Xfail[110X instead of -1, and if the
  result can only be success or failure, [10Xtrue[110X indicates success.[133X
  
  [33X[0;0YAll errors are reported via the [2XLastSystemError[102X ([14XReference: LastSystemError[114X)
  function.[133X
  
  [33X[0;0YIn  the  C  library a lot of integers are defined as macros in header files.
  All  the necessary values for the above functions are bound to their name in
  the global [10XIO[110X record.[133X
  
  [33X[0;0Y[13XWarning:[113X  Existence  of  many  of  these functions and constants is platform
  dependent.  The  compilation  process checks existence and this leads to the
  situation  that  on  the [5XGAP[105X levels the functions and constants are there or
  not.  If  you  want  to  develop  platform  independent  [5XGAP[105X code using this
  package, then you have to check for existence of the functions and constants
  you need.[133X
  
  
  [1X3.1 [33X[0;0YDifferences in arguments - an overview[133X[101X
  
  [33X[0;0YThe  [10Xopen[110X  function  has to be called with three arguments. The version with
  two arguments is not available on the [5XGAP[105X level.[133X
  
  [33X[0;0YThe [10Xread[110X function takes four arguments: [3Xfd[103X is an integer file descriptor, [3Xst[103X
  is  a  [5XGAP[105X  string, [3Xoffset[103X is an offset within this string (zero based), and
  [3Xcount[103X  is  the  maximal number of bytes to read. The data is read and stored
  into  the  string  [3Xst[103X,  starting at position [22X[3Xoffset[103X+1[122X. The string [3Xst[103X is made
  long  enough, such that [3Xcount[103X bytes would fit into it, beginning at position
  [22X[3Xoffset[103X+1[122X. The number of bytes read is returned or [10Xfail[110X in case of an error.[133X
  
  [33X[0;0YThe  [10Xwrite[110X  function  is  similar,  it  also  takes four arguments: [3Xfd[103X is an
  integer file descriptor, [3Xst[103X is a [5XGAP[105X string, [3Xoffset[103X is an offset within this
  string  (zero  based),  and  [3Xcount[103X is the number of bytes to write, starting
  from  position  [22X[3Xoffset[103X+1[122X  in  the  string [3Xst[103X. The number of bytes written is
  returned, or a [10Xfail[110X in case of an error.[133X
  
  [33X[0;0YThe [10Xopendir[110X function only returns [10Xtrue[110X or [10Xfail[110X.[133X
  
  [33X[0;0YThe  [10Xreaddir[110X  function  takes  no  argument. It reads the directory that was
  specified  in  the  last call to [10Xopendir[110X. It just returns a string, which is
  the  name  of  a  file  or  subdirectory  in the corresponding directory. It
  returns  [10Xfalse[110X  after the last file name in the directory or [10Xfail[110X in case of
  an error.[133X
  
  [33X[0;0YThe  [10Xclosedir[110X  function takes no argument. It should be called after [10Xreaddir[110X
  returned [10Xfalse[110X or [10Xfail[110X to avoid excessive use of file descriptors.[133X
  
  [33X[0;0YThe functions [10Xstat[110X, [10Xfstat[110X, and [10Xlstat[110X only take one argument and return a [5XGAP[105X
  record that has the same entries as a [10Xstruct stat[110X.[133X
  
  [33X[0;0YThe  function [10Xsocket[110X can optionally take a string as third argument. In that
  case it automatically calls [10Xgetprotobyname[110X to look up the protocol name.[133X
  
  [33X[0;0YThe  functions  [10Xbind[110X  and  [10Xconnect[110X  take only one string argument as address
  field, because the string already encodes the length.[133X
  
  [33X[0;0YThere   are   two  convenience  functions  [2XIO_make_sockaddr_in[102X  ([14X3.3-1[114X)  and
  [2XIO_MakeIPAddressPort[102X  ([14X4.3-6[114X)  to create such addresses. The first takes two
  arguments  [3Xaddr[103X and [3Xport[103X, where [3Xaddr[103X is a string of length 4, containing the
  4  bytes  of  the  IP  address and [3Xport[103X is a port number as [5XGAP[105X integer. The
  function  [2XIO_MakeIPAddressPort[102X  ([14X4.3-6[114X)  takes  the  same arguments, but the
  first  can  be  a  string  containing  an  IP  address  in dot notation like
  [21X137.226.152.77[121X or a hostname to be looked up.[133X
  
  [33X[0;0YThe  [10Xsetsockopt[110X  function  has  no argument [3Xoptlen[103X. The length of the string
  [3Xoptval[103X is taken.[133X
  
  [33X[0;0YThe [10Xselect[110X function works as the function [10XUNIXSelect[110X in the [5XGAP[105X library.[133X
  
  [33X[0;0YAs  of  now, the file locking mechanisms of [10Xfcntl[110X using [10Xstruct flock[110X are not
  yet implemented on the [5XGAP[105X level.[133X
  
  
  [1X3.2 [33X[0;0YThe low-level functions in detail[133X[101X
  
  [33X[0;0YNearly  all  of this functions return an integer result in the C library. On
  the  [5XGAP[105X  level this is either returned as a non-negative integer in case of
  success  or  as  [9Xfail[109X  in case of an error (where on the C level [22X-1[122X would be
  returned). If the integer can only be [22X0[122X for [21Xno error[121X this is changed to [9Xtrue[109X
  on the [5XGAP[105X level.[133X
  
  [1X3.2-1 IO_accept[101X
  
  [29X[2XIO_accept[102X( [3Xfd[103X, [3Xaddr[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YAccepts  an  incoming  network connection. For details see [21X[10Xman 2 accept[110X[121X. The
  argument  [3Xaddr[103X can be made with [2XIO_make_sockaddr_in[102X ([14X3.3-1[114X) and contains its
  length such that no third argument is necessary.[133X
  
  [1X3.2-2 IO_bind[101X
  
  [29X[2XIO_bind[102X( [3Xfd[103X, [3Xmy_addr[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YBinds  a local address to a socket. For details see [21X[10Xman 2 bind[110X[121X. The argument
  [3Xmy_addr[103X can be made with [2XIO_make_sockaddr_in[102X ([14X3.3-1[114X) and contains its length
  such that no third argument is necessary.[133X
  
  [1X3.2-3 IO_chdir[101X
  
  [29X[2XIO_chdir[102X( [3Xpath[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YChanges the current working directory. For details see [21X[10Xman 2 chdir[110X[121X.[133X
  
  [1X3.2-4 IO_chmod[101X
  
  [29X[2XIO_chmod[102X( [3Xpathname[103X, [3Xmode[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YChanges the mode of a file. For details see [21X[10Xman 2 chmod[110X[121X.[133X
  
  [1X3.2-5 IO_chown[101X
  
  [29X[2XIO_chown[102X( [3Xpath[103X, [3Xowner[103X, [3Xgroup[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YSets owner and/or group of file. For details see [21X[10Xman 2 chown[110X[121X.[133X
  
  [1X3.2-6 IO_close[101X
  
  [29X[2XIO_close[102X( [3Xfd[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YCloses a file descriptor. For details see [21X[10Xman 2 close[110X[121X.[133X
  
  [1X3.2-7 IO_closedir[101X
  
  [29X[2XIO_closedir[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YCloses  a  directory.  For  details  see  [21X[10Xman  3 closedir[110X[121X. Has no arguments,
  because we only have one [10XDIR[110X struct in the C part.[133X
  
  [1X3.2-8 IO_connect[101X
  
  [29X[2XIO_connect[102X( [3Xfd[103X, [3Xserv_addr[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YConnects  to  a  remote  socket. For details see [21X[10Xman 2 connect[110X[121X. The argument
  [3Xserv_addr[103X  can  be  made  with  [2XIO_make_sockaddr_in[102X ([14X3.3-1[114X) and contains its
  length such that no third argument is necessary.[133X
  
  [1X3.2-9 IO_creat[101X
  
  [29X[2XIO_creat[102X( [3Xpathname[103X, [3Xmode[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YCreates a new file. For details see [21X[10Xman 2 creat[110X[121X.[133X
  
  [1X3.2-10 IO_dup[101X
  
  [29X[2XIO_dup[102X( [3Xoldfd[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YDuplicates a file descriptor. For details see [21X[10Xman 2 dup[110X[121X.[133X
  
  [1X3.2-11 IO_dup2[101X
  
  [29X[2XIO_dup2[102X( [3Xoldfd[103X, [3Xnewfd[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YDuplicates a file descriptor to a new one. For details see [21X[10Xman 2 dup2[110X[121X.[133X
  
  [1X3.2-12 IO_execv[101X
  
  [29X[2XIO_execv[102X( [3Xpath[103X, [3Xargv[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xfail[109X or does not return[133X
  
  [33X[0;0YReplaces  the process with another process. For details see [21X[10Xman 3 execv[110X[121X. The
  argument  [3Xargv[103X  is a list of strings. The called program does not have to be
  the first argument in this list.[133X
  
  [1X3.2-13 IO_execve[101X
  
  [29X[2XIO_execve[102X( [3Xpath[103X, [3Xargv[103X, [3Xenvp[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xfail[109X or does not return[133X
  
  [33X[0;0YReplaces the process with another process. For details see [21X[10Xman 3 execve[110X[121X. The
  arguments  [3Xargv[103X  and [3Xenvp[103X are both lists of strings. The called program does
  not  have  to  be the first argument in [3Xargv[103X. The list [3Xenvp[103X can be made with
  [2XIO_MakeEnvList[102X  ([14X4.3-8[114X)  from  a record acquired from [2XIO_Environment[102X ([14X4.3-7[114X)
  and modified later.[133X
  
  [1X3.2-14 IO_execvp[101X
  
  [29X[2XIO_execvp[102X( [3Xpath[103X, [3Xargv[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xfail[109X or does not return[133X
  
  [33X[0;0YReplaces the process with another process. For details see [21X[10Xman 3 execvp[110X[121X. The
  argument  [3Xargv[103X  is a list of strings. The called program does not have to be
  the first argument in this list.[133X
  
  [1X3.2-15 IO_exit[101X
  
  [29X[2XIO_exit[102X( [3Xstatus[103X ) [32X function
  
  [33X[0;0YStops  process  immediately  with  return code [3Xstatus[103X. For details see [21X[10Xman 2
  exit[110X[121X. The argument [3Xstatus[103X must be an integer. Does not return.[133X
  
  [1X3.2-16 IO_fchmod[101X
  
  [29X[2XIO_fchmod[102X( [3Xfd[103X, [3Xmode[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YChanges mode of an opened file. For details see [21X[10Xman 2 fchmod[110X[121X.[133X
  
  [1X3.2-17 IO_fchown[101X
  
  [29X[2XIO_fchown[102X( [3Xfd[103X, [3Xowner[103X, [3Xgroup[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YChanges owner and/or group of an opened file. For details see [21X[10Xman 2 fchown[110X[121X.[133X
  
  [1X3.2-18 IO_fcntl[101X
  
  [29X[2XIO_fcntl[102X( [3Xfd[103X, [3Xcmd[103X, [3Xarg[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YDoes  various  things  to  control  the  behaviour of a file descriptor. For
  details see [21X[10Xman 2 fcntl[110X[121X.[133X
  
  [1X3.2-19 IO_fork[101X
  
  [29X[2XIO_fork[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YForks off a child process, which is an identical copy. For details see [21X[10Xman 2
  fork[110X[121X.  Note that if you want to use the [2XIO_WaitPid[102X ([14X3.2-60[114X) function to wait
  or  check  for  the termination of child processes, you have to activate the
  SIGCHLD   handler   for  this  package  beforehand  by  using  the  function
  [2XIO_InstallSIGCHLDHandler[102X  ([14X3.3-3[114X).  Note  further that after that you cannot
  use       the       function       [2XInputOutputLocalProcess[102X       ([14XReference:
  InputOutputLocalProcess[114X)  any  more, since its SIGCHLD handler does not work
  any   more.   To   switch  back  to  that  functionality  use  the  function
  [2XIO_RestoreSIGCHLDHandler[102X ([14X3.3-4[114X).[133X
  
  [1X3.2-20 IO_fstat[101X
  
  [29X[2XIO_fstat[102X( [3Xfd[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Ya record or [9Xfail[109X[133X
  
  [33X[0;0YReturns  the file meta data for an opened file. For details see [21X[10Xman 2 fstat[110X[121X.
  A [5XGAP[105X record is returned with the same entries than a [10Xstruct stat[110X.[133X
  
  [1X3.2-21 IO_gethostbyname[101X
  
  [29X[2XIO_gethostbyname[102X( [3Xname[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Ya record or [9Xfail[109X[133X
  
  [33X[0;0YReturn  host information by name. For details see [21X[10Xman 3 gethostbyname[110X[121X. A [5XGAP[105X
  record is returned with all the relevant information about the host.[133X
  
  [1X3.2-22 IO_gethostname[101X
  
  [29X[2XIO_gethostname[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Ya string or [9Xfail[109X[133X
  
  [33X[0;0YReturn host name. For details see [21X[10Xman 3 gethostname[110X[121X.[133X
  
  [1X3.2-23 IO_getpid[101X
  
  [29X[2XIO_getpid[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer[133X
  
  [33X[0;0YReturns the process ID of the current process as an integer. For details see
  [21X[10Xman 2 getpid[110X[121X.[133X
  
  [1X3.2-24 IO_getppid[101X
  
  [29X[2XIO_getppid[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer[133X
  
  [33X[0;0YReturns  the  process ID of the parent of the current process as an integer.
  For details see [21X[10Xman 2 getppid[110X[121X.[133X
  
  [1X3.2-25 IO_getsockname[101X
  
  [29X[2XIO_getsockname[102X( [3Xfd[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Ya string or [9Xfail[109X[133X
  
  [33X[0;0YGet a socket name. For details see [21X[10Xman 2 getsockname[110X[121X.[133X
  
  [1X3.2-26 IO_getsockopt[101X
  
  [29X[2XIO_getsockopt[102X( [3Xfd[103X, [3Xlevel[103X, [3Xoptname[103X, [3Xoptval[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfalse[109X[133X
  
  [33X[0;0YGet  a  socket  option.  For  details  see  [21X[10Xman  2 getsockopt[110X[121X. Note that the
  argument  [3Xoptval[103X  carries  its  length  around, such that no 5th argument is
  necessary.[133X
  
  [1X3.2-27 IO_gettimeofday[101X
  
  [29X[2XIO_gettimeofday[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10YA record with components [10Xtv_sec[110X and [10Xtv_usec[110X[133X
  
  [33X[0;0YThis returns the time elapsed since 1.1.1970, 0:00 GMT. The component [10Xtv_sec[110X
  contains  the  number  of full seconds and the number [10Xtv_usec[110X the additional
  microseconds.[133X
  
  [1X3.2-28 IO_gmtime[101X
  
  [29X[2XIO_gmtime[102X( [3Xseconds[103X ) [32X function
  [6XReturns:[106X  [33X[0;10YA record[133X
  
  [33X[0;0YThe argument is the number of seconds that have elapsed since 1.1.1970, 0:00
  GMT. The result is a record with the current Greenwich mean time broken down
  into date and time as in the C-library function [10Xgmtime[110X.[133X
  
  [1X3.2-29 IO_kill[101X
  
  [29X[2XIO_kill[102X( [3Xpid[103X, [3Xsig[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YSends the signal [3Xsig[103X to the process with process ID [3Xpid[103X. For details see [21X[10Xman
  2  kill[110X[121X.  The  signal numbers available can be found in the global [10XIO[110X record
  with names like [10XSIGTERM[110X.[133X
  
  [1X3.2-30 IO_lchown[101X
  
  [29X[2XIO_lchown[102X( [3Xpath[103X, [3Xowner[103X, [3Xgroup[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfalse[109X[133X
  
  [33X[0;0YChanges  owner  and/or  group of a file not following links. For details see
  [21X[10Xman 2 lchown[110X[121X.[133X
  
  [1X3.2-31 IO_link[101X
  
  [29X[2XIO_link[102X( [3Xoldpath[103X, [3Xnewpath[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfalse[109X[133X
  
  [33X[0;0YCreate a hard link. For details see [21X[10Xman 2 link[110X[121X.[133X
  
  [1X3.2-32 IO_listen[101X
  
  [29X[2XIO_listen[102X( [3Xfd[103X, [3Xbacklog[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfalse[109X[133X
  
  [33X[0;0YSwitch a socket to listening. For details see [21X[10Xman 2 listen[110X[121X.[133X
  
  [1X3.2-33 IO_localtime[101X
  
  [29X[2XIO_localtime[102X( [3Xseconds[103X ) [32X function
  [6XReturns:[106X  [33X[0;10YA record[133X
  
  [33X[0;0YThe argument is the number of seconds that have elapsed since 1.1.1970, 0:00
  GMT.  The  result  is  a record with the current local time broken down into
  date and time as in the C-library function [10Xlocaltime[110X.[133X
  
  [1X3.2-34 IO_lseek[101X
  
  [29X[2XIO_lseek[102X( [3Xfd[103X, [3Xoffset[103X, [3Xwhence[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YSeeks within an open file. For details see [21X[10Xman 2 lseek[110X[121X.[133X
  
  [1X3.2-35 IO_lstat[101X
  
  [29X[2XIO_lstat[102X( [3Xname[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Ya record or [9Xfail[109X[133X
  
  [33X[0;0YReturns  the  file meta data for a file not following links. For details see
  [21X[10Xman  2  lstat[110X[121X.  A [5XGAP[105X record is returned with the same entries than a [10Xstruct
  stat[110X.[133X
  
  [1X3.2-36 IO_mkdir[101X
  
  [29X[2XIO_mkdir[102X( [3Xpathname[103X, [3Xmode[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfalse[109X[133X
  
  [33X[0;0YCreates a directory. For details see [21X[10Xman 2 mkdir[110X[121X.[133X
  
  [1X3.2-37 IO_mkfifo[101X
  
  [29X[2XIO_mkfifo[102X( [3Xpathname[103X, [3Xmode[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfalse[109X[133X
  
  [33X[0;0YCreates a FIFO special file (a named pipe). For details see [21X[10Xman 3 mkfifo[110X[121X.[133X
  
  [1X3.2-38 IO_mknod[101X
  
  [29X[2XIO_mknod[102X( [3Xpathname[103X, [3Xmode[103X, [3Xdev[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfalse[109X[133X
  
  [33X[0;0YCreate a special or ordinary file. For details see [21X[10Xman 2 mknod[110X[121X.[133X
  
  [1X3.2-39 IO_open[101X
  
  [29X[2XIO_open[102X( [3Xpathname[103X, [3Xflags[103X, [3Xmode[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YOpen  and possibly create a file or device. For details see [21X[10Xman 2 open[110X[121X. Only
  the variant with 3 arguments can be used.[133X
  
  [1X3.2-40 IO_opendir[101X
  
  [29X[2XIO_opendir[102X( [3Xname[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfalse[109X[133X
  
  [33X[0;0YOpens  a  directory.  For  details see [21X[10Xman 3 opendir[110X[121X. Note that only [9Xtrue[109X is
  returned  if  everything is OK, since only one [10XDIR[110X struct is stored on the C
  level and thus only one directory can be open at any time.[133X
  
  [1X3.2-41 IO_pipe[101X
  
  [29X[2XIO_pipe[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Ya record or [9Xfail[109X[133X
  
  [33X[0;0YCreate  a pair of file descriptors with a pipe between them. For details see
  [21X[10Xman  2 pipe[110X[121X. Note that no arguments are needed. The result is either [9Xfail[109X in
  case of an error or a record with two components [10Xtoread[110X and [10Xtowrite[110X bound to
  the two filedescriptors for reading and writing respectively.[133X
  
  [1X3.2-42 IO_read[101X
  
  [29X[2XIO_read[102X( [3Xfd[103X, [3Xst[103X, [3Xoffset[103X, [3Xcount[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YReads  from  file descriptor. For details see [21X[10Xman 2 read[110X[121X. Note that there is
  one  more  argument [3Xoffset[103X to specify at which position in the string [3Xst[103X the
  read  data should be stored. Note that [3Xoffset[103X zero means at the beginning of
  the  string, which is position 1 in [5XGAP[105X. The number of bytes read or [9Xfail[109X in
  case of an error is returned.[133X
  
  [1X3.2-43 IO_readdir[101X
  
  [29X[2XIO_readdir[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Ya string or [9Xfail[109X or [9Xfalse[109X[133X
  
  [33X[0;0YReads from a directory. For details see [21X[10Xman 2 readdir[110X[121X. Note that no argument
  is  required as we have only one [10XDIR[110X struct on the C level. If the directory
  is  read  completely  [9Xfalse[109X is returned, and otherwise a string. An error is
  indicated by [9Xfail[109X.[133X
  
  [1X3.2-44 IO_readlink[101X
  
  [29X[2XIO_readlink[102X( [3Xpath[103X, [3Xbuf[103X, [3Xbufsize[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YReads  the  value of a symbolic link. For details see [21X[10Xman 2 readlink[110X[121X. [3Xbuf[103X is
  modified. The new length of [3Xbuf[103X is returned or [9Xfail[109X in case of an error.[133X
  
  [1X3.2-45 IO_recv[101X
  
  [29X[2XIO_recv[102X( [3Xfd[103X, [3Xst[103X, [3Xoffset[103X, [3Xlen[103X, [3Xflags[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YReceives data from a socket. For details see [21X[10Xman 2 recv[110X[121X. Note the additional
  argument  [3Xoffset[103X  which  plays  the  same  role  as for the [2XIO_read[102X ([14X3.2-42[114X)
  function.[133X
  
  [1X3.2-46 IO_recvfrom[101X
  
  [29X[2XIO_recvfrom[102X( [3Xfd[103X, [3Xst[103X, [3Xoffset[103X, [3Xlen[103X, [3Xflags[103X, [3Xaddr[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YReceives  data  from  a  socket  with  given  address. For details see [21X[10Xman 2
  recvfrom[110X[121X.  Note  the additional argument [3Xoffset[103X which plays the same role as
  for  the  [2XIO_read[102X  ([14X3.2-42[114X)  function.  The  argument  [3Xaddr[103X can be made with
  [2XIO_make_sockaddr_in[102X  ([14X3.3-1[114X)  and  contains  its  length  such  that  no 7th
  argument is necessary.[133X
  
  [1X3.2-47 IO_rename[101X
  
  [29X[2XIO_rename[102X( [3Xoldpath[103X, [3Xnewpath[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfalse[109X[133X
  
  [33X[0;0YRenames a file or moves it. For details see [21X[10Xman 2 rename[110X[121X.[133X
  
  [1X3.2-48 IO_rewinddir[101X
  
  [29X[2XIO_rewinddir[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YRewinds  a directory. For details see [21X[10Xman 2 rewinddir[110X[121X. Note that no argument
  is  required  as  we  have  only one [10XDIR[110X struct on the C level. Returns [9Xfail[109X
  only, if no prior [2XIO_opendir[102X ([14X3.2-40[114X) command has been called.[133X
  
  [1X3.2-49 IO_rmdir[101X
  
  [29X[2XIO_rmdir[102X( [3Xname[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YRemoves an empty directory. For details see [21X[10Xman 2 rmdir[110X[121X.[133X
  
  [1X3.2-50 IO_seekdir[101X
  
  [29X[2XIO_seekdir[102X( [3Xoffset[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YSets  the  position of the next readdir call. For details see [21X[10Xman 3 seekdir[110X[121X.
  Note  that  no second argument is required as we have only one [10XDIR[110X struct on
  the C level.[133X
  
  [1X3.2-51 IO_select[101X
  
  [29X[2XIO_select[102X( [3Xinlist[103X, [3Xoutlist[103X, [3Xexclist[103X, [3Xtimeoutsec[103X, [3Xtimeoutusec[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YUsed for I/O multiplexing. For details see [21X[10Xman 2 select[110X[121X. [3Xinlist[103X, [3Xoutlist[103X and
  [3Xexclist[103X   are   lists   of  filedescriptors,  which  are  modified.  If  the
  corresponding  file descriptor is not yet ready, it is replaced by [9Xfail[109X. The
  timeout  values [3Xtimeoutsec[103X and [3Xtimeoutusec[103X correspond to the usual arguments
  of [10Xselect[110X, if both are immediate integers, they are set, otherwise [10Xselect[110X is
  called with no timeout value.[133X
  
  [1X3.2-52 IO_send[101X
  
  [29X[2XIO_send[102X( [3Xfd[103X, [3Xst[103X, [3Xoffset[103X, [3Xlen[103X, [3Xflags[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YSends data to a socket. For details see [21X[10Xman 2 send[110X[121X. Note that the additional
  argument [3Xoffset[103X specifies the position of the data to send within the string
  [3Xst[103X.  It  is zero based, meaning that zero indicates the start of the string,
  which is position 1 in [5XGAP[105X.[133X
  
  [1X3.2-53 IO_sendto[101X
  
  [29X[2XIO_sendto[102X( [3Xfd[103X, [3Xst[103X, [3Xoffset[103X, [3Xlen[103X, [3Xflags[103X, [3Xaddr[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YSends  data  to  a  socket.  For  details  see  [21X[10Xman  2 sendto[110X[121X. Note that the
  additional argument [3Xoffset[103X specifies the position of the data to send within
  the  string  [3Xst[103X.  It is zero based, meaning that zero indicates the start of
  the  string,  which is position 1 in [5XGAP[105X. The argument [3Xaddr[103X can be made with
  [2XIO_make_sockaddr_in[102X  ([14X3.3-1[114X)  and  contains  its  length  such  that  no 7th
  argument is necessary.[133X
  
  [1X3.2-54 IO_setsockopt[101X
  
  [29X[2XIO_setsockopt[102X( [3Xfd[103X, [3Xlevel[103X, [3Xoptname[103X, [3Xoptval[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YSets  a  socket  option.  For  details  see  [21X[10Xman 2 setsockopt[110X[121X. Note that the
  argument  [3Xoptval[103X  carries  its  length  around, such that no 5th argument is
  necessary.[133X
  
  [1X3.2-55 IO_socket[101X
  
  [29X[2XIO_socket[102X( [3Xdomain[103X, [3Xtype[103X, [3Xprotocol[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YCreates  a  socket,  an  endpoint  for  communication. For details see [21X[10Xman 2
  socket[110X[121X. There is one little special: On systems that have [10Xgetprotobyname[110X you
  can  pass  a string as third argument [3Xprotocol[103X which is automatically looked
  up by [10Xgetprotobyname[110X.[133X
  
  [1X3.2-56 IO_stat[101X
  
  [29X[2XIO_stat[102X( [3Xpathname[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Ya record or [9Xfail[109X[133X
  
  [33X[0;0YReturns the file metadata for the file [3Xpathname[103X. For details see [21X[10Xman 2 stat[110X[121X.
  A [5XGAP[105X record is returned with the same entries than a [10Xstruct stat[110X.[133X
  
  [1X3.2-57 IO_symlink[101X
  
  [29X[2XIO_symlink[102X( [3Xoldpath[103X, [3Xnewpath[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YCreates a symbolic link. For details see [21X[10Xman 2 symlink[110X[121X.[133X
  
  [1X3.2-58 IO_telldir[101X
  
  [29X[2XIO_telldir[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YReturn  current  location  in directory. For details see [21X[10Xman 3 telldir[110X[121X. Note
  that  no second argument is required as we have only one [10XDIR[110X struct on the C
  level.[133X
  
  [1X3.2-59 IO_unlink[101X
  
  [29X[2XIO_unlink[102X( [3Xpathname[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfail[109X[133X
  
  [33X[0;0YDelete  a  name  and  possibly  the file it refers to. For details see [21X[10Xman 2
  unlink[110X[121X.[133X
  
  [1X3.2-60 IO_WaitPid[101X
  
  [29X[2XIO_WaitPid[102X( [3Xpid[103X, [3Xwait[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Ya record or [9Xfail[109X[133X
  
  [33X[0;0YWaits for the termination of a child process. For details see [21X[10Xman 2 waitpid[110X[121X.
  Returns  a  [5XGAP[105X  record  describing PID and exit status. The second argument
  [3Xwait[103X  must be either [9Xtrue[109X or [9Xfalse[109X. In the first case, the call blocks until
  new information about a terminated child process is available. In the second
  case no such waiting is performed, the call returns immediately. See [2XIO_fork[102X
  ([14X3.2-19[114X).[133X
  
  [1X3.2-61 IO_write[101X
  
  [29X[2XIO_write[102X( [3Xfd[103X, [3Xst[103X, [3Xoffset[103X, [3Xcount[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Yan integer or [9Xfail[109X[133X
  
  [33X[0;0YWrites  to  a  file  descriptor.  For details see [21X[10Xman 2 write[110X[121X. Note that the
  additional argument [3Xoffset[103X specifies the position of the data to send within
  the  string  [3Xst[103X.  It is zero based, meaning that zero indicates the start of
  the string, which is position 1 in [5XGAP[105X.[133X
  
  
  [1X3.3 [33X[0;0YFurther C level functions[133X[101X
  
  [33X[0;0YThe following functions do not correspond to functions in the C library, but
  are there to provide convenience to use other functions:[133X
  
  [1X3.3-1 IO_make_sockaddr_in[101X
  
  [29X[2XIO_make_sockaddr_in[102X( [3Xip[103X, [3Xport[103X ) [32X function
  [6XReturns:[106X  [33X[0;10Ya string or [9Xfail[109X[133X
  
  [33X[0;0YMakes  a struct [10Xsockaddr_in[110X from IP address and port. The IP address must be
  given  as  a  string  of  length  four, containing the four bytes of an IPv4
  address  in  natural order. The port must be a port number. Returns a string
  containing  the  struct, which can be given to all functions above having an
  address argument.[133X
  
  [1X3.3-2 IO_environ[101X
  
  [29X[2XIO_environ[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Ya list of strings[133X
  
  [33X[0;0YFor  details  see  [21X[10Xman environ[110X[121X. Returns the current environment as a list of
  strings of the form [21Xkey=value[121X.[133X
  
  [1X3.3-3 IO_InstallSIGCHLDHandler[101X
  
  [29X[2XIO_InstallSIGCHLDHandler[102X(  ) [32X function
  [6XReturns:[106X  [33X[0;10Y[9Xtrue[109X or [9Xfalse[109X[133X
  
  [33X[0;0YInstalls  our  SIGCHLD  handler. This functions works as an idempotent. That
  is,  calling  it  twice does exactly the same as calling it once. It returns
  [9Xtrue[109X  when  it  is called for the first time since then a pointer to the old
  signal handler is stored in a global variable. See [2XIO_fork[102X ([14X3.2-19[114X).[133X
  
  [1X3.3-4 IO_RestoreSIGCHLDHandler[101X
  
  [29X[2XIO_RestoreSIGCHLDHandler[102X(  ) [32X function
  
  [33X[0;0YRestores the original SIGCHLD handler. This function works as an idempotent.
  That  is,  calling  it  twice  does  exactly the same as calling it once. It
  returns   [9Xtrue[109X   when  it  is  called  for  the  first  time  after  calling
  [2XIO_InstallSIGCHLDHandler[102X ([14X3.3-3[114X). See [2XIO_fork[102X ([14X3.2-19[114X).[133X
  
