void bar(unsigned char * buffer) {
   buffer[49] = 65;
} 

##</code><code>##

use strict;
use warnings;
use Devel::Peek;

use Inline C =><<'EOC';

void foo(SV * buffer) {
  char *data = "Hello there";
  sv_setpv(buffer, data);
}

void bar(unsigned char * buffer) {
  buffer[49] = 65;
}

void _set_CUR(SV * buffer, int bytes) {
  SvCUR_set(buffer, bytes);
}

EOC

my $buffer = 'z' x 60;
Dump $buffer;
foo($buffer);
Dump $buffer;

bar($buffer);
_set_CUR($buffer, 60); # Ensure that Devel::Peek::Dump will display all 60 bytes.
Dump $buffer;

##</code><code>##

SV = PV(0x254ba8dbf08) at 0x254ba920660
  REFCNT = 1
  FLAGS = (POK,pPOK)
  PV = 0x254bce10dc8 "Hello there\x00zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzAzzzzzzzzzz"\0
  CUR = 60
  LEN = 62

##</code><code>##

SV = PV(0x224fe4c0aa0) at 0x224fe4f4cd0
  REFCNT = 1
  FLAGS = (POK,pPOK)
  PV = 0x22480c0e170 "Hello there\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\r\x8B7\xBC\x00\xF8\x00\x88\xC0\x82\x9F\x80$\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10A\x8D\x80$\x02\x00\x00\x00\xB5K\xFE"
  CUR = 60
  LEN = 16