在另一个字符串中查找字符串
Find string in another string
所以我有一个具有以下格式的 .txt 文件：
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:number ，并在第三个文件中打印出电子邮件。唯一的问题是 strstr 对我不起作用，它打印出来所有行，因为我猜 @example.com 全部 emails.I 我将第二个文件中的所有电子邮件保存在一个数组中，然后逐行从第一个文件中读取，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);
}
input.txt:
miani@uniud.it:150995
lucaburiani@libero.it:30000
danybai@hotmail.it:160988
freuzz@alice.it:469375
giozazzu@tiscali.it:30013568
registered.txt:
miani@uniud.it
lucaburiani@libero.it
danybai@hotmail.it
如果需要的话，我正在使用 CodeBlocks。
检测到的问题代码有问题
只需进行最少的修复（这样我就可以在我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);
}
产生这个输出（给定你的数据）：
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
请注意while (!feof(file)) is always wrong。您检查了输入文件是否打开（良好）；你没有检查输出文件是否打开（错误）。
为了调试这个，首先要做的是打印读取的数据，这样你就知道程序看到了什么。令人惊讶的是，计算机看到的东西与您认为它会看到的东西不同。但它是最基本的调试技术之一。
因为您没有正确测试输入，并且因为您有 for(i=0;i<=n;i++)，并且因为您的数组大部分归零，所以您最终会尝试查看是否在数据中找到空字符串，并且是的，每一次。如果您在 printf() 语句中显示正在比较的数据，则可以很容易地发现空字符串。字符串输出周围的方括号（或任何括号字符）可帮助您发现意外字符，例如尾随空格或嵌入式回车 return ('\r') 字符或换行符 ('\n')字符串。
固定码
远非完美，但明显更好：
#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);
}
示例输出：
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
所以我有一个具有以下格式的 .txt 文件：
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:number ，并在第三个文件中打印出电子邮件。唯一的问题是 strstr 对我不起作用，它打印出来所有行，因为我猜 @example.com 全部 emails.I 我将第二个文件中的所有电子邮件保存在一个数组中，然后逐行从第一个文件中读取，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);
}
input.txt:
miani@uniud.it:150995
lucaburiani@libero.it:30000
danybai@hotmail.it:160988
freuzz@alice.it:469375
giozazzu@tiscali.it:30013568
registered.txt:
miani@uniud.it
lucaburiani@libero.it
danybai@hotmail.it
如果需要的话，我正在使用 CodeBlocks。
检测到的问题代码有问题
只需进行最少的修复（这样我就可以在我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);
}
产生这个输出（给定你的数据）：
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
请注意while (!feof(file)) is always wrong。您检查了输入文件是否打开（良好）；你没有检查输出文件是否打开（错误）。
为了调试这个，首先要做的是打印读取的数据，这样你就知道程序看到了什么。令人惊讶的是，计算机看到的东西与您认为它会看到的东西不同。但它是最基本的调试技术之一。
因为您没有正确测试输入，并且因为您有 for(i=0;i<=n;i++)，并且因为您的数组大部分归零，所以您最终会尝试查看是否在数据中找到空字符串，并且是的，每一次。如果您在 printf() 语句中显示正在比较的数据，则可以很容易地发现空字符串。字符串输出周围的方括号（或任何括号字符）可帮助您发现意外字符，例如尾随空格或嵌入式回车 return ('\r') 字符或换行符 ('\n')字符串。
固定码
远非完美，但明显更好：
#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);
}
示例输出：
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