127 lines
3.2 KiB
C
127 lines
3.2 KiB
C
/*
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* C Program to Create Employee Record and Update it
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#define size 200
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struct emp
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{
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int id;
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char *name;
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}*emp1, *emp3;
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void display();
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void create();
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void update();
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FILE *fp, *fp1;
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int count = 0;
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void main(int argc, char **argv)
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{
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int i, n, ch;
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printf("1] Create a Record\n");
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printf("2] Display Records\n");
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printf("3] Update Records\n");
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printf("4] Exit");
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while (1)
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{
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printf("\nEnter your choice : ");
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scanf("%d", &ch);
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switch (ch)
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{
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case 1:
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fp = fopen(argv[1], "a");
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create();
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break;
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case 2:
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fp1 = fopen(argv[1],"rb");
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display();
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break;
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case 3:
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fp1 = fopen(argv[1], "r+");
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update();
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break;
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case 4:
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exit(0);
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}
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}
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}
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/* To create an employee record */
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void create()
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{
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int i;
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char *p;
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emp1 = (struct emp *)malloc(sizeof(struct emp));
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emp1->name = (char *)malloc((size)*(sizeof(char)));
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printf("Enter name of employee : ");
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scanf(" %[^\n]s", emp1->name);
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printf("Enter emp id : ");
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scanf(" %d", &emp1->id);
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fwrite(&emp1->id, sizeof(emp1->id), 1, fp);
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fwrite(emp1->name, size, 1, fp);
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count++; // count to number of entries of records
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fclose(fp);
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}
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/* Display the records in the file */
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void display()
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{
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emp3=(struct emp *)malloc(1*sizeof(struct emp));
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emp3->name=(char *)malloc(size*sizeof(char));
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int i = 1;
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if (fp1 == NULL)
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printf("\nFile not opened for reading");
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while (i <= count)
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{
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fread(&emp3->id, sizeof(emp3->id), 1, fp1);
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fread(emp3->name, size, 1, fp1);
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printf("\n%d %s",emp3->id,emp3->name);
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i++;
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}
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fclose(fp1);
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free(emp3->name);
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free(emp3);
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}
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void update()
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{
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int id, flag = 0, i = 1;
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char s[size];
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if (fp1 == NULL)
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{
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printf("File cant be opened");
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return;
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}
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printf("Enter employee id to update : ");
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scanf("%d", &id);
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emp3 = (struct emp *)malloc(1*sizeof(struct emp));
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emp3->name=(char *)malloc(size*sizeof(char));
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while(i<=count)
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{
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fread(&emp3->id, sizeof(emp3->id), 1, fp1);
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fread(emp3->name,size,1,fp1);
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if (id == emp3->id)
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{
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printf("Enter new name of emplyee to update : ");
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scanf(" %[^\n]s", s);
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fseek(fp1, -204L, SEEK_CUR);
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fwrite(&emp3->id, sizeof(emp3->id), 1, fp1);
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fwrite(s, size, 1, fp1);
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flag = 1;
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break;
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}
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i++;
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}
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if (flag != 1)
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{
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printf("No employee record found");
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flag = 0;
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}
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fclose(fp1);
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free(emp3->name); /* to free allocated memory */
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free(emp3);
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} |