获取指针指向的内存大小

2023-10-10 04:37| 来源: 网络整理| 查看: 265

_msize

Returns the size of a memory block allocated in the heap.

RoutineRequired Header_msize size_t _msize( void *memblock ); Parameters memblock Pointer to memory block Libraries

All versions of the C run-time libraries.

Return Values

_msize returns the size (in bytes) as an unsigned integer.

Remarks

The _msize function returns the size, in bytes, of the memory block allocated by a call to malloc, or realloc.

When the application is linked with a debug version of the C run-time libraries, _msize resolves to _msize_dbg. For more information about how the heap is managed during the debugging process, see Using C Run-Time Library Debugging Support.

Example /* REALLOC.C: This program allocates a block of memory for * buffer and then uses _msize to display the size of that * block. Next, it uses realloc to expand the amount of * memory used by buffer and then calls _msize again to * display the new amount of memory allocated to buffer. */ #include #include #include void main( void ) { long *buffer; size_t size; if( (buffer = (long *)malloc( 1000 * sizeof( long ) )) == NULL ) exit( 1 ); size = _msize( buffer ); printf( "Size of block after malloc of 1000 longs: %u\n", size ); /* Reallocate and show new size: */ if( (buffer = realloc( buffer, size + (1000 * sizeof( long )) )) == NULL ) exit( 1 ); size = _msize( buffer ); printf( "Size of block after realloc of 1000 more longs: %u\n", size ); free( buffer ); exit( 0 ); } Output Size of block after malloc of 1000 longs: 4000 Size of block after realloc of 1000 more longs: 8000 See Also

malloc, realloc

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获取指针 指向的内存大小

获取指针指向的内存大小