C 在另一个字符串中查找字符串

因此，我有一个.txt文件，格式如下：

abc@example.com:number
cde@example.com:number
efg@example.ru:number
And another file with:
abc@example.com
efg@example.ru

我想使用第二个文件中的电子邮件来查找abc@example.com：编号，并在第三个文件中打印电子邮件。唯一的问题是strstr对我不起作用，它打印所有行，因为我猜@example.com在所有电子邮件中。我正在将第二个文件中的所有电子邮件保存在一个数组中，然后逐行读取第一个文件，并使用strstr

    #include <iostream>
#include<stdio.h>
#include<stdlib.h>
#include <string.h>
using namespace std;

int main()
{
FILE *f,*g,*h;
char x[80],y[1000][60];
char *a,*b;
int i,found,n;
i=0;
found=0;
f=fopen("input.txt","r");
g=fopen("registered.txt","r");
h=fopen("output.txt","w");
 if(f==NULL)
        {
        perror("No input!\n");
        exit(1);
        }
 if(g==NULL)
        {
        perror("No registered!\n");
        exit(1);
        }
while(!feof(g))
{
    fscanf(g,"%s",&y[i]);
    i++;
}
n=i;
while(!feof(f))
{
    fscanf(f,"%s",&x);
    a=x;
    for(i=0;i<=n;i++)
    {
        b=y[i];
          if (strstr(a,b)!=NULL)
            {
                fprintf(h,"%s\n",x);
                found++;
            }
    }
}
fclose(f);
fclose(g);
fclose(h);
printf("Found Email:%d\n",found);

}

registered.txt：

miani@uniud.it
lucaburiani@libero.it
danybai@hotmail.it

如果重要的话，我会使用代码块。

问题检测中的断开代码 通过最少的修复（这样我就可以在严格的编译器标志下将其编译为C代码），并添加诊断打印，您的代码的以下变体：

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

int main(void)
{
    FILE *f, *g, *h;
    char x[80], y[1000][60];
    char *a, *b;
    int i, found, n;
    i = 0;
    found = 0;
    f = fopen("input.txt", "r");
    g = fopen("registered.txt", "r");
    h = fopen("output.txt", "w");
    if (f == NULL)
    {
        perror("No input!\n");
        exit(1);
    }
    if (g == NULL)
    {
        perror("No registered!\n");
        exit(1);
    }
    while (!feof(g))
    {
        fscanf(g, "%s", y[i]);
        printf("Registered: [%s]\n", y[i]);
        i++;
    }
    n = i;
    while (!feof(f))
    {
        fscanf(f, "%s", x);
        printf("Scanned: [%s]\n", x);
        a = x;
        for (i = 0; i <= n; i++)
        {
            b = y[i];
            printf("Find: does [%s] contain [%s]?\n", a, b);
            if (strstr(a, b) != NULL)
            {
                printf("Found: [%s] does contain [%s]!\n", a, b);
                fprintf(h, "%s\n", x);
                found++;
            }
        }
    }
    fclose(f);
    fclose(g);
    fclose(h);
    printf("Found Email:%d\n", found);
}

请注意。您检查输入文件是否已打开（良好）；您没有检查输出文件是否已打开（错误）

要进行调试，首先要做的是在读取数据时打印数据，以便知道程序正在看到什么。令人惊讶的是，计算机经常看到你认为它会看到的东西以外的东西。但它是最基本的调试技术之一

---

因为您没有正确地测试输入，因为您有“代码> >（i＝0；IAS使用C++），您可以使用<代码> STD::String …<代码> <代码> <代码>等，并且在您的条件下，一个错误，即代码>代码> STRSTR < /代码>也希望字符串最后搜索，因此调用应该是代码> STRSTR（b，a）你把问题标记为C；你已经在C中编码了问题的正文；但是你在顶部包括C++头。是你还是我被这个问题弄糊涂了？请注意，你检查输入文件是打开的（好）；你没有检查输出文件是打开的（坏的）。谢谢，我感谢你的帮助。

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

int main(void)
{
    FILE *f, *g, *h;
    char x[80], y[1000][60];
    char *a, *b;
    int i, found, n;
    i = 0;
    found = 0;
    f = fopen("input.txt", "r");
    g = fopen("registered.txt", "r");
    h = fopen("output.txt", "w");
    if (f == NULL)
    {
        perror("No input!\n");
        exit(1);
    }
    if (g == NULL)
    {
        perror("No registered!\n");
        exit(1);
    }
    while (!feof(g))
    {
        fscanf(g, "%s", y[i]);
        printf("Registered: [%s]\n", y[i]);
        i++;
    }
    n = i;
    while (!feof(f))
    {
        fscanf(f, "%s", x);
        printf("Scanned: [%s]\n", x);
        a = x;
        for (i = 0; i <= n; i++)
        {
            b = y[i];
            printf("Find: does [%s] contain [%s]?\n", a, b);
            if (strstr(a, b) != NULL)
            {
                printf("Found: [%s] does contain [%s]!\n", a, b);
                fprintf(h, "%s\n", x);
                found++;
            }
        }
    }
    fclose(f);
    fclose(g);
    fclose(h);
    printf("Found Email:%d\n", found);
}

Registered: [miani@uniud.it]
Registered: [lucaburiani@libero.it]
Registered: [danybai@hotmail.it]
Registered: []
Scanned: [miani@uniud.it:150995]
Find: does [miani@uniud.it:150995] contain [miani@uniud.it]?
Found: [miani@uniud.it:150995] does contain [miani@uniud.it]!
Find: does [miani@uniud.it:150995] contain [lucaburiani@libero.it]?
Find: does [miani@uniud.it:150995] contain [danybai@hotmail.it]?
Find: does [miani@uniud.it:150995] contain []?
Found: [miani@uniud.it:150995] does contain []!
Find: does [miani@uniud.it:150995] contain []?
Found: [miani@uniud.it:150995] does contain []!
Scanned: [lucaburiani@libero.it:30000]
Find: does [lucaburiani@libero.it:30000] contain [miani@uniud.it]?
Find: does [lucaburiani@libero.it:30000] contain [lucaburiani@libero.it]?
Found: [lucaburiani@libero.it:30000] does contain [lucaburiani@libero.it]!
Find: does [lucaburiani@libero.it:30000] contain [danybai@hotmail.it]?
Find: does [lucaburiani@libero.it:30000] contain []?
Found: [lucaburiani@libero.it:30000] does contain []!
Find: does [lucaburiani@libero.it:30000] contain []?
Found: [lucaburiani@libero.it:30000] does contain []!
Scanned: [danybai@hotmail.it:160988]
Find: does [danybai@hotmail.it:160988] contain [miani@uniud.it]?
Find: does [danybai@hotmail.it:160988] contain [lucaburiani@libero.it]?
Find: does [danybai@hotmail.it:160988] contain [danybai@hotmail.it]?
Found: [danybai@hotmail.it:160988] does contain [danybai@hotmail.it]!
Find: does [danybai@hotmail.it:160988] contain []?
Found: [danybai@hotmail.it:160988] does contain []!
Find: does [danybai@hotmail.it:160988] contain []?
Found: [danybai@hotmail.it:160988] does contain []!
Scanned: [freuzz@alice.it:469375]
Find: does [freuzz@alice.it:469375] contain [miani@uniud.it]?
Find: does [freuzz@alice.it:469375] contain [lucaburiani@libero.it]?
Find: does [freuzz@alice.it:469375] contain [danybai@hotmail.it]?
Find: does [freuzz@alice.it:469375] contain []?
Found: [freuzz@alice.it:469375] does contain []!
Find: does [freuzz@alice.it:469375] contain []?
Found: [freuzz@alice.it:469375] does contain []!
Scanned: [giozazzu@tiscali.it:30013568]
Find: does [giozazzu@tiscali.it:30013568] contain [miani@uniud.it]?
Find: does [giozazzu@tiscali.it:30013568] contain [lucaburiani@libero.it]?
Find: does [giozazzu@tiscali.it:30013568] contain [danybai@hotmail.it]?
Find: does [giozazzu@tiscali.it:30013568] contain []?
Found: [giozazzu@tiscali.it:30013568] does contain []!
Find: does [giozazzu@tiscali.it:30013568] contain []?
Found: [giozazzu@tiscali.it:30013568] does contain []!
Scanned: [giozazzu@tiscali.it:30013568]
Find: does [giozazzu@tiscali.it:30013568] contain [miani@uniud.it]?
Find: does [giozazzu@tiscali.it:30013568] contain [lucaburiani@libero.it]?
Find: does [giozazzu@tiscali.it:30013568] contain [danybai@hotmail.it]?
Find: does [giozazzu@tiscali.it:30013568] contain []?
Found: [giozazzu@tiscali.it:30013568] does contain []!
Find: does [giozazzu@tiscali.it:30013568] contain []?
Found: [giozazzu@tiscali.it:30013568] does contain []!
Found Email:15

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

int main(void)
{
    FILE *f, *g, *h;
    char x[80], y[1000][60];
    char *a, *b;
    int i, found, n;
    i = 0;
    found = 0;
    f = fopen("input.txt", "r");
    g = fopen("registered.txt", "r");
    h = fopen("output.txt", "w");
    if (f == NULL)
    {
        perror("No input.txt!\n");
        exit(1);
    }
    if (g == NULL)
    {
        perror("No registered.txt!\n");
        exit(1);
    }
    if (h == NULL)
    {
        perror("No output.txt!\n");
        exit(1);
    }
    while (fscanf(g, "%s", y[i]) == 1)
    {
        printf("Registered: [%s]\n", y[i]);
        i++;
    }
    n = i;
    while (fscanf(f, "%s", x) == 1)
    {
        printf("Scanned: [%s]\n", x);
        a = x;
        for (i = 0; i < n; i++)
        {
            b = y[i];
            printf("Find: does [%s] contain [%s]\n", a, b);
            if (strstr(a, b) != NULL)
            {
                printf("Match: %s\n", x);
                fprintf(h, "%s\n", x);
                found++;
                break;
            }
        }
    }
    fclose(f);
    fclose(g);
    fclose(h);
    printf("Found Email: %d\n", found);
}

Registered: [miani@uniud.it]
Registered: [lucaburiani@libero.it]
Registered: [danybai@hotmail.it]
Scanned: [miani@uniud.it:150995]
Find: does [miani@uniud.it:150995] contain [miani@uniud.it]
Match: miani@uniud.it:150995
Scanned: [lucaburiani@libero.it:30000]
Find: does [lucaburiani@libero.it:30000] contain [miani@uniud.it]
Find: does [lucaburiani@libero.it:30000] contain [lucaburiani@libero.it]
Match: lucaburiani@libero.it:30000
Scanned: [danybai@hotmail.it:160988]
Find: does [danybai@hotmail.it:160988] contain [miani@uniud.it]
Find: does [danybai@hotmail.it:160988] contain [lucaburiani@libero.it]
Find: does [danybai@hotmail.it:160988] contain [danybai@hotmail.it]
Match: danybai@hotmail.it:160988
Scanned: [freuzz@alice.it:469375]
Find: does [freuzz@alice.it:469375] contain [miani@uniud.it]
Find: does [freuzz@alice.it:469375] contain [lucaburiani@libero.it]
Find: does [freuzz@alice.it:469375] contain [danybai@hotmail.it]
Scanned: [giozazzu@tiscali.it:30013568]
Find: does [giozazzu@tiscali.it:30013568] contain [miani@uniud.it]
Find: does [giozazzu@tiscali.it:30013568] contain [lucaburiani@libero.it]
Find: does [giozazzu@tiscali.it:30013568] contain [danybai@hotmail.it]
Found Email: 3