C語言解析http請求表單內容

[1].[文件] cgi.h?~?405B????下載(105) 跳至 [1] [2] [3] [4] [5] [6] [7] [8]

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#ifndef CGI_H
#define CGI_H
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct Node{
????char *name;
????char *value;
????struct Node *next;
}Node;
typedef struct Index{
????Node *head;
????char *buffer;
}Index;
Index *get_input();
void free_input(Index *);
Node *analyze(char *);
Node *analy_a(char *);
Node *analy_m(char *, char  *);
char *get_value(Node *, char *);
char fun1(char);
#endif

[2].[文件] get_input.c?~?965B????下載(85) 跳至 [1] [2] [3] [4] [5] [6] [7] [8]

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#include "cgi.h"
Index *get_input() {
????//獲得表單發送方法
????char *get_method = getenv("REQUEST_METHOD");
????Index *input = (Index *)malloc(sizeof(Index));
????Node *head;
????char *buffer;
????if (strcmp(get_method,"GET") == 0) {
????????char *get_str = getenv("QUERY_STRING");
????????if (get_str == NULL || *get_str == 0) {
????????????return NULL;
????????}
????????//get方法，通過環境變量得到內容
????????buffer = (char *)malloc(strlen(get_str) + 1);
????????strcpy(buffer, get_str);
????????//對內容進行解析，以鏈表的形式存在
????????head = analy_a(buffer);
????} else  if (strcmp(get_method,"POST") == 0){
????????int get_len = atoi(getenv("CONTENT_LENGTH"));
????????if (get_len == 0) {
????????????return NULL;
????????}
????????//post方法，通過標準輸入讀取內容
????????buffer = (char *)malloc(get_len + 1);
????????memset(buffer,0,get_len + 1);
????????int n = fread(buffer, 1,get_len, stdin);
????????if (n != get_len) {
????????????fprintf(stderr,"Read error!");
????????}
????????head = analyze(buffer);
????}
????//鏈表頭
????input -> head = head;
????//接受到的字符串
????input -> buffer = buffer;
????return input;
}

[3].[文件] analyze.c?~?610B????下載(81) 跳至 [1] [2] [3] [4] [5] [6] [7] [8]

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#include "cgi.h"
//post方法獲取的內容進行解析
Node *analyze(char *buffer) 
{
????//獲取內容格式
????char *c_type = getenv("CONTENT_TYPE");
????char *bound;
????fprintf(stderr,"debug:c_type is %s\n",c_type);
????if (strcmp("application/x-www-form-urlencoded",c_type) == 0) {
????????//該格式表明獲取內容為"name=value"形式
????????return analy_a(buffer);???? 
????} else  if (strcmp("text/plain", c_type) == 0) {
????????//此種編碼格式暫不討論
????} else {
????????//編碼格式為multipart/form-data，適用大流量數據傳送
????????//獲取等號后面的分隔符
????????bound = index(c_type,'=') + 1;
????????fprintf(stderr,"debug:bound is %s\n",bound);
????????return analy_m(buffer, bound);
????}
}

[4].[文件] analy_a.c?~?961B????下載(78) 跳至 [1] [2] [3] [4] [5] [6] [7] [8]

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#include "cgi.h"
//編碼格式為'application/x-www-form-urlencoded'的內容
Node *analy_a(char *buffer) 
{
????//創建第一個節點
????Node *head = (Node *)malloc(sizeof(Node));
????Node *temp = head;
????temp -> name = buffer;
????char *b_temp = buffer;
????//通過移動、改變部分字符來分離字符串
????while (*buffer != 0) {
????????if (*buffer == '=') {
????????????//'='，則表示name已經結束，value將開始
????????????*b_temp = 0;
????????????temp -> value = b_temp + 1;? 
????????}else if (*buffer ==  '+') {
????????????//'+'代表空格
????????????*b_temp = ' ';
????????}else if (*buffer ==  '%') {
????????????//'%'則緊跟兩位十六進制表示的特殊字符
????????????*b_temp = fun1(*(buffer + 1)) * 16 + fun1(*(buffer + 2));
????????????buffer += 2;
????????}
????????else if (*buffer ==  '&') {
????????????//'&'表示value已經結束，name即將開始
????????????*b_temp = 0;
????????????//重新申請內存，存儲新內容地址
????????????temp -> next = (Node *)malloc(sizeof(Node));
????????????temp = temp -> next;
????????????temp -> name = b_temp + 1;?? 
????????}else {
????????????*b_temp = *buffer;
????????}
????????buffer++;
????????b_temp++;?????????? 
????}
????//最后一個結束符
????*b_temp = 0;
????return head;
}

[5].[文件] analy_m.c?~?1KB????下載(80) 跳至 [1] [2] [3] [4] [5] [6] [7] [8]

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#include "cgi.h"
//編碼格式為'multipart/form-data'的內容
Node *analy_m(char *buffer, char *bound) 
{
????char *start;
????char *end;
????//第一個節點
????Node *head = (Node*)malloc(sizeof(Node));
????Node *temp = head;
????fprintf(stderr,"debug:buffer is %s\n", buffer);
????//開始解析內容，name在兩個雙引號之間(詳見編碼格式)
????temp -> name = index(buffer, '"') + 1;
????end = index(temp -> name, '"');
????*end = 0;
????fprintf(stderr,"debug:temp->name is %s\n", temp -> name);
????//中間間隔了兩個"\r\n"
????temp -> value = end + 5;
????buffer = strstr(temp -> value, bound);
????//到下一個間隔符，上面間隔兩個"\r\n"
????*(buffer - 4) = 0;
????fprintf(stderr,"debug:temp->valu is %s\n", temp -> value);
????while ((start = strstr(buffer,"name=")) != NULL) {
????????//循環獲取name與value地址，直到沒有name為止
????????temp -> next = (Node *)malloc(sizeof(Node));
????????temp = temp -> next;
????????temp -> name = index(start, '"') + 1;
????????end = index(temp -> name, '"');
????????*end = 0;
????????fprintf(stderr,"debug:temp->name is %s\n", temp -> name);
????????temp -> value = end + 5;
????????buffer = strstr(temp -> value, bound);
????????*(buffer - 4) = 0;
????????fprintf(stderr,"debug:temp->valu is %s\n", temp -> value);
????}
????return head;
}

[6].[文件] fun1.c?~?203B????下載(76) 跳至 [1] [2] [3] [4] [5] [6] [7] [8]

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//將十六進制字符轉化為十進制數
char  fun1(char ch)
{
????char buffer;
????if (ch < 'A') {
????????buffer = ch - 48;?????????????????????????? 
????}else if (ch < 'a'){
????????buffer = ch - 55;
????}else {
????????buffer = ch - 87;
????}
????return buffer;? 
}

[7].[文件] get_value.c?~?241B????下載(77) 跳至 [1] [2] [3] [4] [5] [6] [7] [8]

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#include "cgi.h"
//根據name獲取相應的value
char  *get_value(Node *head, char  *name)
{?? 
????Node *p;
????while (head != NULL) {
????????if (strcmp(head -> name, name) == 0) {
????????????return head -> value;
????????}
????????p = head -> next;
????????head = p;
????}
????return NULL;
}

[8].[文件] free_input.c?~?222B????下載(79) 跳至 [1] [2] [3] [4] [5] [6] [7] [8]

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#include "cgi.h"
//釋放動態獲取的內存
void  free_input(Index *index)
{
????Node *temp = index -> head;
????Node *p;
????while (temp != NULL) {
????????p = temp -> next;
????????free(temp);
????????temp = p;
????}
????free(index -> buffer);
????free(index);
}