khajavi

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

#include <sys/io.h>

khajavi

#include <stdio.h>
#include <stdint.h>
#include <unistd.h>
#include <inttypes.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/utsname.h>

khajavi

// weibo上有人说到https://github.com/joewalnes/websocketd，我想其原理大致如此（process-wrapper.c）:

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

int wrap_process(const char* exefile) {

khajavi

#include <stdio.h>
#include <unistd.h>
#include <stdint.h>
#include <linux/fd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>

#define BLKSSZGET  _IO(0x12,104)/* get block device sector size */

khajavi

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kthread.h>

struct task_struct* ts;

static int thread_func(void)
{
    while (1)
    {

khajavi

count_words: count_words.o lexer.o -lfl
	gcc count_words.o lexer.o -lfl -o count_words

count_words.o: count_words.c
	gcc -c count_words.c

lexer.o: lexer.c
	gcc -c lexer.c

lexer.c: lexer.l

khajavi

#include <stdio.h>
int main() { printf("Hello, World!\n"); }

khajavi

#include <stdlib.h> //getenv, atoi
#include <stdio.h> //printf

int main() {
  char* reps_text = getenv("reps");
  int reps = reps_text ? atoi( reps_text ) : 10;

  char* msg = getenv( "msg" );
  if (!msg) msg = "Hello.";

khajavi

#include <stdlib.h>
#include <stdio.h>


int main( int argc, char **argv, char **envp ) {
  char **env;

  for( env = envp; *env; env++ ) 
    printf( "%s\n", *env );

khajavi

#include <stdio.h>
extern char **environ;

void main()
{
    for (char **env = environ; *env; ++env)
        printf("%s\n", *env);
}