Programming

==10228== Syscall param socketcall.sendto(msg) points to uninitialised byte(s)
==10228== at 0x4EF65B5: send (in /lib/libc-2.7.so)
==10228== by 0x4030B4: functionname (includefile.h:249)
==10228== by 0x403976: main (program.c:28)
==10228== Address 0x517d89a is 18 bytes inside a block of size 20 alloc'd
==10228== at 0x4C2260E: malloc (vg_replace_malloc.c:207)
==10228== by 0x40307C: functionname (includefile.h:247)
==10228== by 0x403976: main (program.c:28)

Originally Posted by achenle

Your fixed-lenght text is only 6 characters, not 8. The substring "\r\n" is two bytes - carriage return and linefeed, not four bytes.

Originally Posted by cyler

I get this Valgrind error while using malloc but if I use calloc then there is no error.

I allocate 8 bytes for the string inside sprintf, 12 for the ip and 1 for the string terminator. This totals 21, so why is it talking about 20 bytes and 18 bytes ?

Originally Posted by cyler

Partial code:

Code:

char ip[] = "80.80.80.80";
int buffer = 8 + strlen(ip);         // buffer=19 becoz strlen excludes the terminating null byte
char *headers = malloc(buffer + 1);  // malloc allocates 20 bytes
sprintf(headers, " -r %s\r\n", ip);  // this is 18 bytes becoz sprintf adds a null byte at the end
send(foobar, headers, buffer, 0);