READ(2)                 GENIX Programmer's Manual                 READ(2)



      NAME
           read - read from file

      SYNOPSIS
           read(fildes, buffer, nbytes)
           char *buffer;

      DESCRIPTION
           A file descriptor is a word returned from a successful open,  creat,
           dup,  or  pipe  call.   Buffer  is the location of nbytes contiguous
           bytes into which the input will be placed.   It  is  not  guaranteed
           that  all  nbytes bytes will be read; for example if the file refers
           to a typewriter at most one line will be returned.  In any event the
           number of characters read is returned.

           If the returned value is 0, then end-of-file has been reached.

           Unless the reader is ignoring or holding SIGTTIN signals, reads from
           the  control  typewriter  while  not  in  its  process group cause a
           SIGTTIN signal to be sent to the  reader's  process  group;  in  the
           former case an end-of-file is returned.

      SEE ALSO
           open(2), creat(2), dup(2), pipe(2), vread(2)

      DIAGNOSTICS
           As mentioned, 0 is returned when  the  end  of  the  file  has  been
           reached.  If the read was otherwise unsuccessful the return value is
           -1.  Many conditions can generate an error: physical I/O errors, bad
           buffer  address, preposterous nbytes, file descriptor not that of an
           input file.
























      Printed 11/16/83                                                        1