html - 在 C 中使用 CGI 将 HTML 表单数据文件上传到服务器？

Question

我将一个 HTML 表单放入 C 语言的 CGI 文件中，并使用如下 fprintf 语句:

<form action="cgi-bin/upload.cgi" method="post" enctype="multipart/form-data"> 
    <p>Photo to Upload: <input type="file" name="photo" /></p> 
    <p>Your Email Address: <input type="text" name="email_address" /></p> 
    <p><input type="submit" name="Submit" value="Submit Form" /></p> 
</form>

我想知道是否可以获取文件输入(从具有多部分/表单数据正文的表单请求的值)，将其转换为 C 代码(通过获取 url 数据处理值)，然后上传从那里归档？顺便说一句，我不允许使用 PHP，因为我目前使用的机器空间非常有限。

Answer 1

此示例不使用任何非标准库:

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

#define MAXLEN 80
#define EXTRA 5
/* 4 for field name "data", 1 for "=" */
#define MAXINPUT MAXLEN + EXTRA + 2
/* 1 for added line break, 1 for trailing NUL */
#define DATAFILE "../data/data.txt"

void unencode(char * src, char * last, char * dest) {
    for (; src != last; src++, dest++)
        if ( * src == '+')
            * dest = ' ';
        else if ( * src == '%') {
        int code;
        if (sscanf(src + 1, "%2x", & code) != 1) code = '?'; * dest = code;
        src += 2;
    } else
        *dest = * src; * dest = '\n'; * ++dest = '\0';
}

int main(void) {
    char * lenstr;
    char input[MAXINPUT], data[MAXINPUT];
    long len;
    printf("%s%c%c\n",
        "Content-Type:text/html;charset=iso-8859-1", 13, 10);
    printf("<TITLE>Response</TITLE>\n");
    lenstr = getenv("CONTENT_LENGTH");
    if (lenstr == NULL || sscanf(lenstr, "%ld", & len) != 1 || len > MAXLEN)
        printf("<P>Error in invocation - wrong FORM probably.");
    else {
        FILE * f;
        fgets(input, len + 1, stdin);
        unencode(input + EXTRA, input + len, data);
        f = fopen(DATAFILE, "a");
        if (f == NULL)
            printf("<P>Sorry, cannot store your data.");
        else
            fputs(data, f);
        fclose(f);
        printf("<P>Thank you! The following contribution of yours has \
been stored:<BR>%s", data);
    }
    return 0;
}