glibc/libio/fileops.c

2    This file is part of the GNU C Library.
20    As a special exception, if you link the code in this file with
24    however invalidate any other reasons why the executable file
83    in external file system is normally _IO_read_end, except in putback
86    the file as a whole corresponding to eGptr(). (?)
93    that _IO_read_end corresponds to the external file position.)
101    The OS file position corresponds to that of egptr().
133   /* POSIX.1 allows another file handle to be used to change the position
134      of our file descriptor.  Hence we actually don't know the actual
136   fp->file._offset = _IO_pos_BAD;
137   fp->file._IO_file_flags |= CLOSED_FILEBUF_FLAGS;
140   fp->file._fileno = -1;
413   /* Get the current position of the file. */
601 /* Guts of underflow callback if we mmap the file.  This stats the file and
603    If the file is no longer eligible for mmap, its jump tables are reset to
612       /* Limit the file size to 1MB for 32-bit machines.  */
620 	  /* We can trim off some pages past the end of the file.  */
629 	  /* The file added some pages.  We need to remap it.  */
670       /* If we are already positioned at or past the end of the file, don't
713 /* Special callback replacing the underflow callbacks if we mmap the file.  */
721     /* We punted to the regular file functions.  */
735 	/* We use the file in read-only mode.  This could mean we can
736 	 * mmap the file and use it without any copying.  But not all
737 	 * file descriptors are for mmap-able objects and on 32-bit
745 		/* Limit the file size to 1MB for 32-bit machines.  */
750 		/* Try to map the file.  */
760 			/* OK, we managed to map the file.  Set the buffer up and use a
762 			 * never tries to read anything from the file.
795 	/* We couldn't use mmap, so revert to the vanilla file operations. */
946   /* POSIX.1 8.2.3.7 says that after a call the fflush() the file
947      offset of the underlying file must be exact.  */
1117   /* We need to do it since it is possible that the file offset in
1119      we fopen a file and then do a fork. One process may access the
1120      the file and the kernel file offset will be changed. */
1170     /* One can fseek arbitrarily past the end of the file
1175     /* Adjust the read pointers to match the file position,
1247   /* In addition to closing the file descriptor we have to unmap the file.  */
1510 	  /* Check that we are mapping all of the file, in case it grew.  */