This manual page is for Mac OS X version 10.6.3

Reading manual pages

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 pointers 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 humanreadable
     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 ALSO
     dladdr(3), malloc(3)

Mac OS X                                      February 15, 2007                                     Mac OS X