比较两个文件时出现段错误[关闭]

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[<15小时前关闭。

我正在c中创建一个文本编辑器，我想在其中添加比较两个文件的功能。因此，下面是我在其中创建比较功能的代码部分。但是由于某些错误，会弹出错误。

为了记录（我在代码中定义了int line, col;)。

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

int line, col;
int i,j,ch;
char fn[20],e,c,name[64];
FILE *fp1,*fp2,*fp;

void NewFile();
void Copy();
void Delete();
void Display();
void comparison();

void main()
{
    do {
        printf("\n\t\t***** TEXT EDITOR *****");
        printf("\n\n\tMENU:\n\t\n");
        printf("\n\t1.NEWFILE\t2.DISPLAY\t3.COPY\t\t4.DELETE\t5.COMPARISON\t6.EXIT\n");
        printf("\n\tEnter your choice: ");
        scanf("%d",&ch);
    switch(ch)
            {
            case 1:
            NewFile();
            break;
            case 2:
            Display();
            break;
            case 3:
            Copy();
            break;
            case 4:
            Delete();
            break;
            case 5:
            comparison();
            break;
            case 6:
            exit(0);
            }
            }while(1);

    }
    void NewFile()
        {
        printf("\n\tEnter the name of the file to be created: ");
        scanf("%s", name);
        fp1=fopen(name,"w");
        printf("\n\tEnter the text and press '.' to save\n\n\t");
        while(1)
        {
            c=getchar();
            fputc(c,fp1);
                if(c == '.')
                {
                fclose(fp1);
                break;
                }
        }
        }

void comparison()
{
    printf("\n\tEnter the first file: ");
        scanf("%s", name);
        fp1=fopen(name,"r");
    printf("\n\tEnter the second file: ");
        scanf("%s", name);
        fp2=fopen(fn,"r");  
    int *line = 0;
    int *col  = 0;
    do{ 
    c = getc(fp1);
    e = getc(fp2);

    if (c == '\n')
        {
            *line += 1;
            *col = 0;
        }
    if (c != e)
        printf("Files not equal");
    else
        *col += 1;
    }while(c != EOF && e != EOF);

    if (c == EOF && e == EOF)
        printf("Files are equal");
    else
        printf("Files not equal");
}


void Display()
{
printf("\n\tEnter the file name: ");
scanf("%s",fn);
fp1=fopen(fn,"r");
if(fp1==NULL)
{
printf("\n\tFile not found!");
fclose(fp1);
printf("\n\n\tPress any key to continue\n");
}
while(!feof(fp1))
{
c=getc(fp1);
printf("%c",c);
}

}
void Copy()
{
printf("\n\tEnter the new filename to copy:  ");
scanf("%s",fn);
printf("\n\tEnter the filename from which to copy: ");
scanf("%s", name);
fp1=fopen(name,"r");
fp2=fopen(fn,"w");
while(!feof(fp1))
{
c=getc(fp1);
putc(c,fp2);
}
printf("\n\tFile has been copied successfully");
fclose(fp2);
}

void Delete()
{
printf("\n\tEnter the file name: ");
scanf("%s",fn);
fp1=fopen(fn,"r");
if(fp1==NULL)
{
printf("\n\tFile not found!");
goto end2;
}
fclose(fp1);
if(remove(fn)==0)
{
printf("\n\n\tFile has been deleted successfully!");
goto end2;
}
else
printf("\n\tError!\n");
end2: printf("\n\n\tPress any key to continue\n");
}

错误：
Segmentation fault (core dumped)

请提出一些建议。预先感谢。    

Answer 1

您在此职位上犯的主要错误：

printf("\n\tEnter the first file: ");
scanf("%s", name);
fp1=fopen(name,"r");
printf("\n\tEnter the second file: ");
scanf("%s", name);
         // ^^^^
fp2=fopen(fn,"r");
       // ^^ (never assigned)

正确的功能代码：
#include <string.h>

void comparison()
{
    printf("\n\tEnter the first file: ");
    scanf("%s", name);
    fp1 = fopen(name, "r");
    printf("\n\tEnter the second file: ");
    scanf("%s", fn);
    fp2 = fopen(fn, "r");
    int pC, pE;
    do
    {
        pC = getc(fp1);
        pE = getc(fp2);

        if (pC == '\n')
        {
            line += 1;
            col = 0;
        }
        if (pC != pE)
            printf("Files not equal");
        else
            col += 1;
    } while (pC != EOF && pE != EOF);

    if (pC == EOF && pE == EOF)
        printf("Files are equal");
    else
        printf("Files not equal");
}

您已经全局声明了变量，这可能会给您带来不确定的行为。为了解决这个问题，我创建并替换了本地函数使用的所有变量。
该代码应该对您有用。
其他错误：
在发生最严重的错误之后，您所犯的错误是您试图使用也在其他函数中使用的全局变量，它们可能会提供未定义的行为。
main()必须返回您的代码违反的整数。
feof()永远不会给出正确的结果。避免使用它。
[注释中描述了程序中分段错误的正确原因。