Tribblix: manual page: elf

ELF_ERRMSG(3ELF) ELF Library Functions ELF_ERRMSG(3ELF)

NAME

elf_errmsg, elf_errno - error handling

SYNOPSIS

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

const char *elf_errmsg(int err);

int elf_errno(void);

DESCRIPTION

If an ELF library function fails, a program can call elf_errno() to
retrieve the library's internal error number. As a side effect, this
function resets the internal error number to 0, which indicates no
error.

The elf_errmsg() function takes an error number, err, and returns a
null-terminated error message (with no trailing new-line) that
describes the problem. A zero err retrieves a message for the most
recent error. If no error has occurred, the return value is a null
pointer (not a pointer to the null string). Using err of -1 also
retrieves the most recent error, except it guarantees a non-null
return value, even when no error has occurred. If no message is
available for the given number, elf_errmsg() returns a pointer to an
appropriate message. This function does not have the side effect of
clearing the internal error number.

EXAMPLES

Example 1: A sample program of calling the elf_errmsg() function.

The following fragment clears the internal error number and checks it
later for errors. Unless an error occurs after the first call to
elf_errno(), the next call will return 0.

(void)elf_errno();
/* processing ... */
while (more_to_do)
{
if ((err = elf_errno()) != 0)
{
/* print msg */
msg = elf_errmsg(err);
}
}