| Function | Description |
| emalloc() | Serves as replacement for malloc(). |
| efree() | Serves as replacement for free(). |
| estrdup() | Serves as replacement for strdup(). |
| estrndup() | Serves as replacement for strndup(). Faster than estrdup() and binary-safe. This is the recommended function to use if you know the string length prior to duplicating it. |
| ecalloc() | Serves as replacement for calloc(). |
| erealloc() | Serves as replacement for realloc(). |
emalloc(), estrdup(), estrndup(), ecalloc(), and erealloc() allocate internal memory; efree() frees these previously allocated blocks. Memory handled by the e*() functions is considered local to the current process and is discarded as soon as the script executed by this process is terminated.
Warning
To allocate resident memory that survives termination of the current script, you can use malloc()and free(). This should only be done with extreme care, however, and only in conjunction with demands of the Zend API; otherwise, you risk memory leaks.