02-27-2002
When you open() a file you create an entry in the system file table and you get an fd that points to that file table entry. The file table entry has an integer called the file pointer that indicates the next byte to be read or wriitten in the file. As you read the file, the file pointer gets updated.
When you duplicate an fd by any means such as dup(), fcntrl(), or even fork(), you get new fd's that point to the same file table entry.
If you want two file pointers to the same file, you must have two file table entries in which to store them. That means two open() calls.
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--------------
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LEARN ABOUT CENTOS
uildumpsymboltable
UilDumpSymbolTable(library call) UilDumpSymbolTable(library call)
NAME
UilDumpSymbolTable -- Dumps the contents of a named UIL symbol table to standard output
SYNOPSIS
#include <uil/UilDef.h>
void UilDumpSymbolTable(
sym_entry_type *root_ptr);
DESCRIPTION
The UilDumpSymbolTable function dumps the contents of a UIL symbol table pointer to standard output.
root_ptr Specifies a pointer to the the symbol table root entry. This value can be taken from the parse_tree_root part of the Uil_com-
pile_desc_type data structure returned by Uil.
By following the link from the root entry, you can traverse the entire parse tree. Symbol table entries are in the following format:
hex.address symbol.type symbol.data prev.source.position source.position modification.record
where:
hex.address
Specifies the hexadecimal address of this entry in the symbol table.
symbol.type
Specifies the type of this symbol table entry. Some possible types are root, module, value, procedure, and widget.
symbol.data
Specifies data for the symbol table entry. The data varies with the type of the entry. Often it contains pointers to other symbol
table entries, or the actual data for the data type.
prev.source.position
Specifies the end point in the source code for the previous source item.
source.position
Specifies the range of positions in the source code for this symbol.
The exact data structures for each symbol type are defined in the include file UilSymDef.h. Note that this file is automatically included
when an application includes the file UilDef.h.
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Uil(3)
UilDumpSymbolTable(library call)