elf_errmsg,
elf_errno
—
ELF library error message handling
ELF Access Library (libelf, -lelf)
#include
<libelf.h>
int
elf_errno(
void);
const char *
elf_errmsg(
int
error);
When an error occurs during an ELF library API call, the library encodes the
error using an error number and stores the error number internally for
retrieval by the application at a later point of time. Error numbers may
contain an OS supplied error code in addition to an ELF API specific error
code. An error number value of zero indicates no error.
Function
elf_errno() is used to retrieve the last
error recorded by the ELF library. Invoking this function has the side-effect
of resetting the ELF library's recorded error number to zero.
The function
elf_errmsg() returns a null-terminated
string with a human readable description of the error specified in argument
error. A zero value for argument
error retrieves the most recent error
encountered by the ELF library. An argument value of -1 behaves identically,
except that it guarantees a non-NULL return from
elf_errmsg().
Function
elf_errno() returns a non-zero value
encoding the last error encountered by the ELF library, or zero if no error
was encountered.
Function
elf_errmsg() returns a pointer to library
local storage for non-zero values of argument
error. With a zero argument, the function
will return a NULL pointer if no error had been encountered by the library, or
will return a pointer to library local storage containing an appropriate
message otherwise.
Clearing the ELF library's recorded error number can be accomplished by invoking
elf_errno() and discarding its return value.
/* clear error */
(void) elf_errno();
Retrieving a human-readable description of the current error number can be done
with the following snippet:
int err;
const char *errmsg;
...
err = elf_errno();
if (err != 0)
errmsg = elf_errmsg(err);
elf(3),
gelf(3)
Function
elf_errmsg() is not localized.