NLIST(3ELF) ELF Library Functions NLIST(3ELF)

NAME

nlist - get entries from name list

SYNOPSIS

cc [ flag... ] file ... -lelf [ library ... ]
#include <nlist.h>

int nlist(const char *filename, struct nlist *nl);

DESCRIPTION

nlist() examines the name list in the executable file whose name is
pointed to by filename, and selectively extracts a list of values and
puts them in the array of nlist() structures pointed to by nl. The name
list nl consists of an array of structures containing names of variables,
types, and values. The list is terminated with a null name, that is, a
null string is in the name position of the structure. Each variable name
is looked up in the name list of the file. If the name is found, the
type, value, storage class, and section number of the name are inserted
in the other fields. The type field may be set to 0 if the file was not
compiled with the -g option to cc.


nlist() will always return the information for an external symbol of a
given name if the name exists in the file. If an external symbol does not
exist, and there is more than one symbol with the specified name in the
file (such as static symbols defined in separate files), the values
returned will be for the last occurrence of that name in the file. If the
name is not found, all fields in the structure except n_name are set to
0.


This function is useful for examining the system name list kept in the
file /dev/ksyms. In this way programs can obtain system addresses that
are up to date.

RETURN VALUES

All value entries are set to 0 if the file cannot be read or if it does
not contain a valid name list.


nlist() returns 0 on success, -1 on error.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Stable |
+--------------------+-----------------+
|MT-Level | Safe |
+--------------------+-----------------+

SEE ALSO

elf(3ELF), kvm_nlist(3KVM), kvm_open(3KVM), libelf(3LIB), ksyms(4D),
mem(4D), a.out(5), attributes(7)

July 11, 2001 NLIST(3ELF)