Does memcpy check for NULL?

No, memcpy(0,0,0) is not safe. The standard library will likely not fail on that call. However in a testing envirenment, some extra code might be present in memcpy() to detect buffer overruns and other problems. And how that special version of memcpy() reacts to NULL pointers is, well, undefined.

Does strlen include Null?

size_t strlen(const char* s) strlen(s) returns the length of null-terminated string s. The length does not count the null character. For example, strlen(“rabbit”) = 6.

What can be used instead of memcpy?

What is memmove()? memmove() is similar to memcpy() as it also copies data from a source to destination. memcpy() leads to problems when source and destination addresses overlap as memcpy() simply copies data one by one from one location to another.

Is memcpy deprecated?

As some of you may know, Microsoft banned memcpy() from their Security Development Lifecycle, replacing it with memcpy_s() .

When to null terminate a string in memcpy?

Thanks to Naveen for pointing out the off-by-one error in your terminating null. I’ve taken the liberty of using your return value to indicate the length of the returned string, or the number of characters required if the length passed in was <= 0. If you want to treat the buffer as a string you should NULL terminate it.

Are there any compilers that assume memcpy pointers are non null?

Some compilers will use this corner of the standard to assume that pointers passed to memcpyare non-NULL, irrespective of the length argument. GCC has built this in, while Clang can get it from the fact that glibc annotates memcpywith nonnullspecifications. Consider the following function:

What is a null value in mysql table?

A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this field. Then, the field will be saved with a NULL value. Note: A NULL value is different from a zero value or a field that contains spaces.

How does the memcpy function copy N characters?

The memcpy function copies n characters from the object pointed to by s2 into the object pointed to by s1. Apart from a prohibition on passing overlapping objects, I think every C programmer understands that. However, the standard also says (section 7.1.4):