我正在c中进行库存管理项目。在项目中我需要删除记录。我发现要执行此操作删除记录工作我必须搜索特定记录并将其他记录写入临时文件，并在删除原始文件后将其重命名为原始文件名。 但是在我的项目代码中，某些重命名语句正在跳过。
这是我的项目代码。
#include<stdio.h>
#include <string.h>
#include <stdlib.h>
#include<inttypes.h>
#include<windows.h>
struct record_stu
{
unsigned long long int id;
int gm;
char subject[255],s[255],y[255];
};
main()
{
struct record_stu st;
FILE *fp,*fp_tmp;
char c,subject[255],year[255],semester[255];
unsigned long long int id;
int gm,j,z;
int records=0;
const char* charString1 = "Student_ID";
const char* charString2 = "Subject";
const char* charString3 = "Year";
const char* charString4 = "Semester";
const char* charString5 = "Gained_Marks";
const char* charString6 = "Yes";
const char* charString7 = "No";
//const char* charString8 = "CSE-4year1.dat";
fp = fopen("CSE-4Year1.dat","r");
if(!(fp))
{
printf("An Error has occurred.Department can't be Found\n");
}
else
{
printf("Department Found.\n");
printf("Select a Specific Record to Delete!");
printf("\nEnter Student ID\n");
scanf("%"PRIu64"",&id);
printf("\nEnter subject\n");
scanf("%s",subject);
printf("\nEnter Year\n");
scanf("%s",year);
printf("\nEnter Semester\n");
scanf("%s",semester);
printf("%s\t%s\t%s\t%s\t%s\n",charString1,charString2,charString3,charString4,charString5);
rewind(fp);
while (!feof(fp))
{
fscanf(fp,"%11"PRIu64"\t%3s\t%3s\t%3s\t%10d", &st.id, &st.subject, &st.y, &st.s,&st.gm);
records++;
fp_tmp = fopen("temp.dat","a");
if(st.id==id)
{
if(strcmp(st.subject,subject)==0)
{
if(strcmp(st.y,year)==0)
{
if(strcmp(st.s,semester)==0)
{
printf("%11"PRIu64"\t%3s\t%3s\t%3s\t%10d\n", st.id,st.subject, st.y, st.s, st.gm);
printf("Are Sure You Want This Record to be Deleted?(Yes(1)/No(2))\n");
scanf("%d",&z);
if(z==1)
{
printf("%11"PRIu64"\t%3s\t%3s\t%3s\t%10d\n", st.id,st.subject, st.y, st.s, st.gm);
}
else if(z==2)
{
break;
}
else
{
printf("Wrong Input.Pleas check case of your input.\n");
break;
}
}
}
}
}
else
{
fprintf(fp_tmp,"%11"PRIu64"\t%3s\t%3s\t%3s\t%10d\n", st.id, st.subject, st.y, st.s,st.gm);
}
}
}
fclose(fp);
fclose(fp_tmp);
remove("CSE-4Year1.dat");
if (rename("temp.dat","CSE-4Year1.dat") == 0)
printf("Renamed successfully");
else
printf("Unable to rename the file");
break;
有趣的是我有一个小代码来重命名它的工作正常。虽然小代码和项目代码的语法基本相同。
请尽快帮助。
小代码在这里
#include<stdio.h>
main()
{
//remove("b.txt");
rename("temp.dat","CSE-4Year1.dat");
}
答案 0 :(得分：0)
这是完整的代码。重命名问题消失了。如果文件已打开或目录中不存在，则会发生重命名问题。
#include<stdio.h>
#include <string.h>
#include <stdlib.h>
#include<inttypes.h>
#include<windows.h>
//Variable Declarations
struct record_stu st;
FILE *fp,*fp_tmp,*fp1,*f,*f1;
unsigned long long int id;
char Selected_Exam[255],subject[255],Exam[255],year[255];
char semester[255],Dept_name[255],username[55],username_log[55], pass1[8];
char pass2[8],pasword[10],usrname[10],ch,pasword1[10];
char usrname1[10],Course_Code[255],ss[255],s1[255] = "";
char s2[255] = "",Gained_Letter_Grade[255],filename,lg,ct[255],cc[255],ct1[255];
int Course_Code_Number,i,gm,j=0,z,n=0,i,cs=0;
int flag=0,records=0,x[12],Dept_code,Gained_Mark,p=0;
float Gained_Grade_Point,Credit_Completed,gp,cd,tgp=0,tcd=0,cgpa=0,sgpa,pgp,ccr;
const char* charString1 = "Exam";
const char* charString2 = "Student_ID";
const char* charString3 = "Department Name";
const char* charString4 = "Course Code";
const char* charString5 = "Year";
const char* charString6 = "Semester";
const char* charString7 = "Letter Grade";
const char* charString8 = "Gained Mark";
const char* charString9 = "Grade Point";
const char* charString10 = "Credit Completed";
const char* charString11 = "Course Title";
const char* charString12 = "Yes";
const char* charString13 = "No";
struct record_stu
{
unsigned long long int id;
float sgpa;
int gm;
float gp,cd,ccr;
char Exam[255],subject[255],semester[255],year[255];
char Dept_name[255],Exam1[255],lg[255],ct[255],cc[255],ct1[255];
};
//Variable Declarations
main()
{
//File open command
fp = fopen("Student - Copy.txt","r");
fp_tmp = fopen("temp.txt","w");
//File Open Command
if(!(fp)) //File Open Error Detection
{
printf("An Error has occurred.File can't be Found\n");
}
else //Searching for the record to delete
{
fclose(fp_tmp);
fclose(fp);
printf("File Found.\n");
rewind(fp);
printf("\nEnter Student ID: ");
scanf("%"PRIu64"",&id);
printf("\nEnter Course Code:");
scanf("%s",subject);
fp = fopen("Student - Copy.txt","r");
fp_tmp = fopen("temp.txt","w");
while (fscanf(fp,"%s %"PRIu64"%s%s%s%s%s%d%f%f%s\n",st.Exam1,&st.id,st.Dept_name,st.subject,st.year,st.semester,&st.lg,&st.gm,&st.gp,&ccr,&st.ct1) != EOF)
{
records++;
if(st.id==id && strcmp(st.subject,subject)==0)
{
printf("Do you want to delete the record?(Yes(1)/No(2))\nEnter Your Choice: ");
scanf("%d",&z);
printf("Confirmation Code = %d\n",z);
if(z==1)
{
printf("Do you want to confirm deletion of the record?(Yes(1)/No(2))\nEnter Your Choice: ");
scanf("%d",&p);
}
}
else
{
fprintf(fp_tmp,"%s %11"PRIu64"\t%s\t%s\t%3s\t%3s\t%s\t%d\t%3.2f\t%f\t%s\n",st.Exam1,st.id,st.Dept_name,st.subject,st.year,st.semester,st.lg,st.gm,st.gp,ccr,st.ct1);
}
}
}//Searching for the record to delete
//Actual Delete operation by renaming the temporary file to the source file name
if(p==1)
{
printf("Confirmation Code = %d\n",p);
fclose(fp_tmp);
fclose(fp);
remove("Student - Copy.txt");
if(rename("temp.txt","Student - Copy.txt")==0)
printf("Delete Successful");
}
else
{
fclose(fp_tmp);
fclose(fp);
printf("Delete Unsuccessful");
remove("temp.txt");
}
//Actual Delete operation by renaming the temporary file to the source file name
}