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memswap(3pub) [debian man page]

MEMSWAP(3pub)						       C Programmer's Manual						     MEMSWAP(3pub)

NAME

       memswap - swap the contents of two memory blocks

SYNOPSIS

       #include <publib.h>
       void memswap(void *block1, void *block2, size_t n);

DESCRIPTION

       memswap	will  swap  the  contents  of  the  two blocks pointed by its first two arguments.  The last argument gives the size of the memory
       blocks.

EXAMPLE

       To swap two structs, one might do the following.

	    struct tm tm1, tm2;

	    memswap(&tm1, &tm2, sizeof(struct tm));

BUGS

       Using memswap to swap small portions of memory is inefficient.  It is not worth it to use it to swap variables of any of the  basic  types,
       for instance.  Use inline code for such cases.  However, for large portions of memory, e.g., arrays, it is convenient.

       memswap	can't  swap variables whose address can't be taken.  This excludes variables with the register specifier and bitfields in structs.
       But then, there is no way to write a function (or macro) that can handle any kind of arguments.	Life is hard.

SEE ALSO

       publib(3)

AUTHOR

       Lars Wirzenius (lars.wirzenius@helsinki.fi)

Publib							       C Programmer's Manual						     MEMSWAP(3pub)

Check Out this Related Man Page

STRMAXCPY(3pub) 					       C Programmer's Manual						   STRMAXCPY(3pub)

NAME

       strmaxcpy - copy at most a given number of characters of string

SYNOPSIS

       #include <publib.h>
       char *strmaxcpy(char *tgt, const char *src, size_t n);

DESCRIPTION

       strmaxcpy copies up to n-1 characters from the beginning of src to tgt, then adds a ''.  n must be at least 1.  The target string must be
       large enough to hold the result.

       Note that unlike strncpy(3), this function always terminates the result with ''.  It also doesn't fill the result with extra '' charac-
       ters.

RETURN VALUE

       strmaxcpy returns its first argument.

EXAMPLE

       To  print  out  the  first 69 characters of a string, you might do the following (although familiarity with printf's format string might be
       more useful in this case).

	    #include <stdio.h>
	    #include <publib.h>

	    void print42(const char *string) {
		 char copy[43]; /* 42 + '' */

		 puts(strmaxcpy(copy, string, sizeof(copy)));
	    }

SEE ALSO

       publib(3), strncpy(3)

AUTHOR

       Lars Wirzenius (lars.wirzenius@helsinki.fi)

Publib							       C Programmer's Manual						   STRMAXCPY(3pub)
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