Intro
The C way to print anything to a file, the console or even to memory
is printf and friend functions which are defined in <stdio.h>.
printf is still absolutely viable with mulle-obj. To print an
object with standard printf, you would use the objects -UTF8String method:
printf( "%s\n", [obj UTF8String]);
But when objects are involved it is more convenient to use the
mulle_printf family of functions. mulle_printf allows the special ‘%@’
object conversion. This simplifies the code to:
mulle_printf( "%@\n", obj);
Internally the same thing happens, the -UTF8String method of obj is
called and the result is used to replace %@.
Functions with C format strings
Functions with normal arguments
| stdio | mulle | Description |
|---|---|---|
printf |
mulle_printf |
print to stdout |
fprintf |
mulle_fprintf |
print to FILE |
dprintf |
- | print to file descriptor |
sprintf |
mulle_sprintf |
print to “big enough” char buffer |
snprintf |
mulle_snprintf |
print to char buffer of given size |
There are some non-POSIX extensions which are available on BSD and Linux for C. The mulle functions are available on all platforms.
| stdio | mulle | Description |
|---|---|---|
asprintf |
mulle_asprintf |
allocate char buffer and print to char buffer of given size with varargs (C) |
vasprintf |
mulle_vasprintf |
allocate char buffer and print to char buffer of given size with varargs (C) |
Functions with C varargs
The vprintf variants accept stdarg parameters. This is convenient for
forwarding arguments in a C function, that itself accepts variable arguments.
| stdio | mulle | Description |
|---|---|---|
vprintf |
mulle_vprintf |
print to stdout with stdarg (C) |
vfprintf |
mulle_vfprintf |
print to FILE with stdarg (C) |
vdprintf |
- | print to file descriptor with stdarg (C) |
vsprintf |
mulle_vsprintf |
print to “big enough” char buffer with stdarg (C) |
vsnprintf |
mulle_vsnprintf |
print to char buffer of given size with stdarg (C) |
Functions with mulle-varargs
Methods with variable arguments don’t receive stdarg arguments but mulle-varargs arguments. There is support for this as well.
| Function | Description |
|---|---|
mulle_mvprintf |
print to stdout with mulle-varargs (Objective-C) |
mulle_mvfprintf |
print to FILE with mulle-varargs (Objective-C) |
mulle_mvsprintf |
print to “big enough” char buffer with mulle-varargs (Objective-C) |
mulle_mvsnprintf |
print to char buffer of given size with mulle-varargs (Objective-C) |
mulle_mvasprintf |
allocate char buffer and print with mulle-varargs (Objective-C) |
Functions printing into autoreleased C strings
With asprintf a malloced string is returned. The caller should
free this string eventually. Wouldn’t it be convenient, if the string was
already autoreleased, so the caller wouldn’t have to free it ?
You can create such autoreleases C strings like so:
char *s;
s = MulleObjC_asprintf( "%d", 1848);
The following mulle functions create autoreleased C strings:
| Function | Description |
|---|---|
MulleObjC_asprintf |
allocate autoreleased char buffer and print to it |
MulleObjC_vasprintf |
allocate autoreleased char buffer and print to it with varargs (C) |
MulleObjC_mvasprintf |
allocate autoreleased char buffer and print to it with mulle-varargs (Objective-C) |
Functions with Objective-C format strings
MulleObjCPrintf( @"%@\n", @VfL Bochum 1848") is basically the same as
mulle_printf( ["@%s\n" UTF8String], @"VfL Bochum 1848\n").
MulleObjC supports Objective-C format strings with the following functions:
| C | Objective-C | Description |
|---|---|---|
mulle_printf |
MulleObjCPrintf |
print to stdout |
mulle_vprintf |
MulleObjCVPrintf |
print to stdout with stdarg (C) |
mulle_mvprintf |
MulleObjCVPrintf |
print to stdout with mulle-vararg (Objective-C) |
mulle_fprintf |
MulleObjCFPrintf |
print to FILE |
mulle_vfprintf |
MulleObjCVPrintf |
print to FILE with stdarg (C) |
mulle_mvfprintf |
MulleObjCMVPrintf |
print to FILE with mulle-vararg (Objective-C) |
For all other purposes use the NSString stringWithFormat: methods.