>replace [...] with [...]
Code:
#include <stdio.h>
#include <ctype.h>
int main(void)
{
const char text[] = "Hello World 125!", *ptr;
puts("A:");
for ( ptr = text; *ptr; ++ptr )
{
int result = (*ptr & 0xDF) | (~(*ptr & 0x20) & 0x20);
printf(isprint(result) ? "%c" : "<%d>", result);
}
puts("\nB:");
for ( ptr = text; *ptr; ++ptr )
{
int result = islower(*ptr) ? toupper(*ptr) :
isupper(*ptr) ? tolower(*ptr) : *ptr;
printf(isprint(result) ? "%c" : "<%d>", result);
}
putchar('\n');
return 0;
}
/* my output
A:
hELLO<0>wORLD<0><17><18><21><1>
B:
hELLO wORLD 125!
*/