Wiki source for KeyPgFBMemcopy
{{fbdoc item="title" value="FB_MEMCOPY"}}----
Copies a block of memory from a location to another
{{fbdoc item="syntax"}}##
[[KeyPgDeclare|declare]] [[KeyPgFunction|function]] **fb_memcopy** [[KeyPgCdecl|cdecl]] ( [[KeyPgByref|byref]] //dst// [[KeyPgAs|as]] [[KeyPgAny|any]], [[KeyPgByref|byref]] //src// [[KeyPgAs|as]] [[KeyPgAny|any]], [[KeyPgByval|byval]] //bytes// [[KeyPgAs|as]] [[KeyPgUinteger|uinteger]] ) [[KeyPgAs|as]] [[KeyPgAny|any]] [[KeyPgPtr|ptr]]
##
{{fbdoc item="usage"}}##
[//result// =] **fb_memcopy**( //dst//, //src//, //bytes// )
##
{{fbdoc item="param"}}
##//dst//##
starting address of destination memory
##//src//##
starting address of source memory
##//bytes//##
number of bytes to copy
{{fbdoc item="ret"}}
The starting address of destination memory is returned.
{{fbdoc item="desc"}}
##**fb_memcopy**## copies a given number of bytes from the memory location ##//src//## to the memory location ##//dst//##.
Each starting address is taken from a reference to a variable or array element.
The memory areas must not overlap (otherwise, the copying is not guaranteed to work properly, especially depending on the platform). Use ##[[KeyPgFBMemmove|fb_memmove]]## preferably when the memory areas do overlap (safer approach).
To avoid overflows, the valid memory areas pointed to by both ##//src//## and ##//dst//## must be at least equal in size to the number of bytes to be copied.
The underlying type of the objects pointed to by both the source and destination pointers are irrelevant for this function.
The function does not check for any terminating null character in the source area. It always copies exactly the given number of bytes.
The result is a binary copy of the data.
**Note:** In order to copy from/to memory referenced by a ##[[KeyPgPtr|Pointer]]##, it must be dereferenced first (or else specify in argument term the ##[[KeyPgByval|Byval]]## keyword in front of the pointer name). Otherwise, ##**fb_memcopy**## will try to copy the bytes from/to the **pointer variable**'s memory location.
{{fbdoc item="ex"}}
{{fbdoc item="filename" value="examples/manual/array/memcopy.bas"}}%%(freebasic)
Type Person
Dim As Zstring * 40 name
Dim As Integer age
End Type
Dim As Zstring Ptr mynameptr = @"Pierre de Fermat"
Dim As Person person1, person2
' using fb_memcopy to copy string
fb_memcopy(person1.name, *mynameptr, Len(*mynameptr) + 1)
person1.age = 46
' using fb_memcopy to copy structure
fb_memcopy(person2, person1, Sizeof(Person))
Print person2.name, person2.age
Sleep
%%Output:
%%
Pierre de Fermat 46
%%
{{fbdoc item="ver"}}
- Since fbc 1.08.0
{{fbdoc item="diff"}}
- The behavior and usage is new to ""FreeBASIC"".
{{fbdoc item="see"}}
- ##[[KeyPgFBMemcopyclear|fb_memcopyclear]]##
- ##[[KeyPgFBMemmove|fb_memmove]]##
{{fbdoc item="back" value="CatPgMemory|Memory Functions"}}
Copies a block of memory from a location to another
{{fbdoc item="syntax"}}##
[[KeyPgDeclare|declare]] [[KeyPgFunction|function]] **fb_memcopy** [[KeyPgCdecl|cdecl]] ( [[KeyPgByref|byref]] //dst// [[KeyPgAs|as]] [[KeyPgAny|any]], [[KeyPgByref|byref]] //src// [[KeyPgAs|as]] [[KeyPgAny|any]], [[KeyPgByval|byval]] //bytes// [[KeyPgAs|as]] [[KeyPgUinteger|uinteger]] ) [[KeyPgAs|as]] [[KeyPgAny|any]] [[KeyPgPtr|ptr]]
##
{{fbdoc item="usage"}}##
[//result// =] **fb_memcopy**( //dst//, //src//, //bytes// )
##
{{fbdoc item="param"}}
##//dst//##
starting address of destination memory
##//src//##
starting address of source memory
##//bytes//##
number of bytes to copy
{{fbdoc item="ret"}}
The starting address of destination memory is returned.
{{fbdoc item="desc"}}
##**fb_memcopy**## copies a given number of bytes from the memory location ##//src//## to the memory location ##//dst//##.
Each starting address is taken from a reference to a variable or array element.
The memory areas must not overlap (otherwise, the copying is not guaranteed to work properly, especially depending on the platform). Use ##[[KeyPgFBMemmove|fb_memmove]]## preferably when the memory areas do overlap (safer approach).
To avoid overflows, the valid memory areas pointed to by both ##//src//## and ##//dst//## must be at least equal in size to the number of bytes to be copied.
The underlying type of the objects pointed to by both the source and destination pointers are irrelevant for this function.
The function does not check for any terminating null character in the source area. It always copies exactly the given number of bytes.
The result is a binary copy of the data.
**Note:** In order to copy from/to memory referenced by a ##[[KeyPgPtr|Pointer]]##, it must be dereferenced first (or else specify in argument term the ##[[KeyPgByval|Byval]]## keyword in front of the pointer name). Otherwise, ##**fb_memcopy**## will try to copy the bytes from/to the **pointer variable**'s memory location.
{{fbdoc item="ex"}}
{{fbdoc item="filename" value="examples/manual/array/memcopy.bas"}}%%(freebasic)
Type Person
Dim As Zstring * 40 name
Dim As Integer age
End Type
Dim As Zstring Ptr mynameptr = @"Pierre de Fermat"
Dim As Person person1, person2
' using fb_memcopy to copy string
fb_memcopy(person1.name, *mynameptr, Len(*mynameptr) + 1)
person1.age = 46
' using fb_memcopy to copy structure
fb_memcopy(person2, person1, Sizeof(Person))
Print person2.name, person2.age
Sleep
%%Output:
%%
Pierre de Fermat 46
%%
{{fbdoc item="ver"}}
- Since fbc 1.08.0
{{fbdoc item="diff"}}
- The behavior and usage is new to ""FreeBASIC"".
{{fbdoc item="see"}}
- ##[[KeyPgFBMemcopyclear|fb_memcopyclear]]##
- ##[[KeyPgFBMemmove|fb_memmove]]##
{{fbdoc item="back" value="CatPgMemory|Memory Functions"}}
