backtrace(3) BSD Library Functions Manual backtrace(3)NAME
backtrace, backtrace_symbols, backtrace_symbols_fd — call stack backtrace
and display functions
SYNOPSIS
#include <execinfo.h>
int
backtrace(void** array, int size);
char**
backtrace_symbols(void* const* array, int size);
void
backtrace_symbols_fd(void* const* array, int size, int fd);
DESCRIPTION
These routines provide a mechanism to examine the current thread's call
stack.
backtrace() writes the function return addresses of the current call
stack to the array of pointers referenced by array. At most, size point‐
ers are written. The number of pointers actually written to array is
returned.
backtrace_symbols() attempts to transform a call stack obtained by
backtrace() into an array of human-readable strings using dladdr(). The
array of strings returned has size elements. It is allocated using
malloc() and should be released using free(). There is no need to free
the individual strings in the array.
backtrace_symbols_fd() performs the same operation as
backtrace_symbols(), but the resulting strings are immediately written to
the file descriptor fd, and are not returned.
EXAMPLE
#include <execinfo.h>
#include <stdio.h>
...
void* callstack[128];
int i, frames = backtrace(callstack, 128);
char** strs = backtrace_symbols(callstack, frames);
for (i = 0; i < frames; ++i) {
printf("%s\n", strs[i]);
}
free(strs);
...
HISTORY
These functions first appeared in Mac OS X 10.5.
SEE ALSOdladdr(3), malloc(3)Mac OS X February 15, 2007 Mac OS X