흔한_반도의_뻘짓.c

pperlgit.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#define CHUNK_SIZE 128

//I will not use NULL terminated string for performance.
typedef struct charwithlen_struct {
  char *data;
  size_t len;
} charwithlen_t;

charwithlen_t nullappend = {
  .data = "\0",
  .len = 1
};

int append_data(charwithlen_t *target, charwithlen_t *appenddata) {
  target -> data = realloc(target -> data, target -> len + appenddata -> len);

  if (target -> data == NULL) {
    exit(-1);
  }
  
  memcpy(target -> data + target -> len, appenddata -> data, appenddata -> len);
  
  target -> len = target -> len + appenddata -> len;
}

int main(int argc, char **argv) {
  charwithlen_t chunk;

  chunk.data = malloc(CHUNK_SIZE);
  chunk.len = 0;

  charwithlen_t readdata = {
    .data = NULL,
    .len = 0
  };

  charwithlen_t writedata = {
    .data = NULL,
    .len = 0
  };

  charwithlen_t buf;

  buf.data = malloc(1000);
  buf.len = 0;
  
  do {
    char str[1000];
    int read_ret = read(STDIN_FILENO, chunk.data, 10);

    if(read_ret < 0) {
      break;
    } else {
      chunk.len = read_ret;
    }
  
    int len = sprintf(str, "%d", chunk.len);
  
    if(chunk.len != 0)
      append_data(&readdata, &chunk);
    
  } while (chunk.len != 0);

  append_data(&readdata, &nullappend);

  int a, b;
  
  sscanf(readdata.data, "%d %d", &a, &b);

  buf.len = snprintf(buf.data, 1000, "%d", a+b);

  append_data(&writedata, &buf);
  
  write(STDOUT_FILENO, buf.data, buf.len);
  return 0;
}