ALLOCA(3) | Library Functions Manual | ALLOCA(3)

# NAME

`alloca` — memory allocator

# SYNOPSIS

`#include <stdlib.h>`

void *
`alloca`(size_t size);

# DESCRIPTION

The `alloca`() function allocates size bytes of space in the stack frame of the caller. This temporary space is automatically freed on return.

# RETURN VALUES

The `alloca`() function returns a pointer to the beginning of the allocated space.

# SEE ALSO

pagesize(1), brk(2), malloc(3)

# CAVEATS

The `alloca`() function is unsafe because it cannot ensure that the pointer returned points to a valid and usable block of memory. The allocation made may exceed the bounds of the stack, or even go further into other objects in memory, and `alloca`() cannot determine such an error. Avoid `alloca`() with large unbounded allocations.

January 17, 2015 | Debian