http server v0.1_http_webapp.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
/*-----------------------------------------------------------------

functionname: file_exist
param:  NA
return: NA
author: xxxx

    check if file is exist in webapp
    history:
    create by xxxx, 2014.1.08, add simple abilities
-------------------------------------------------------------*/
int file_exist(char* url)
{
    int ret;
    int len = ;
    char* path= NULL;

    if(url == NULL)
        return -;

    len = strlen(url);
    if(len  <= )
        return -;

    path = (char*)malloc(len);
    strncpy(path, url, len);

    printf("[%s]\n", path);
    // remove blanks on head and tailof url
    ret = access(path, R_OK);
    if(ret == -)
        perror("uri not exist");

    free(path);
    return ret;     

}

long get_file_size(FILE* fs)
{
    if(fs == NULL)
        return -;

    fseek(fs, , SEEK_END);
    return ftell(fs);
}

char *itoa(int num, char *str, int radix)
{
        //0的情况
        if (num==)
        {
                str[]='';
                str[]='\0';
                return str;
        }

        char string[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

        char* ptr = str;
        int i;
        int j;

        while (num)
        {
                *ptr++ = string[num % radix];
                num /= radix;

                if (num < radix)
                {
                        *ptr++ = string[num];
                        *ptr = '\0';
                        break;
                }
        }
        //两边对调
        j = ptr - str - ;

        for (i = ; i < (ptr - str) / ; i++)
        {
                int temp = str[i];
                str[i] = str[j];
                str[j--] = temp;
        }

        return str;
}

int io_write(int fd, void *usrbuf, int n)
{
    int nleft = n;
    int nwritten;
    char *bufp = usrbuf;

    while (nleft > ) {
    if ((nwritten = write(fd, bufp, nleft)) <= ) {
        if (errno == EINTR)  /* interrupted by sig handler return */
        nwritten = ;    /* and call write() again */
        else
        return -;       /* errorno set by write() */
    }
    nleft -= nwritten;
    bufp += nwritten;
    }
    return n;
}

#ifndef __HTTP_WEBAPP_H
#define __HTTP_WEBAPP_H

int file_exist(char* url);
long get_file_size(FILE* fs);
int io_write(int fd, void *usrbuf, int n);
char *itoa(int num, char *str, int radix);

#endif