File is collection of records or is a place on hard disk, where data is stored permanently.
Operations on files
The operations on files in C programming language are as follows −
- Naming the file
- Opening the file
- Reading from the file
- Writing into the file
- Closing the file
Syntax
The syntax for opening a file is as follows −
FILE *File pointer;
For example, FILE * fptr;
The syntax for naming a file is as follows −
File pointer = fopen ("File name", "mode");For example,
fptr = fopen ("sample.txt", "r");
FILE *fp;
fp = fopen ("sample.txt", "w");fgets( ) and fputs( ) functions
fgets( ) is used for reading a string from a file.
The syntax for fgets() function is as follows −
fgets (string variable, No. of characters, File pointer);
For example,
FILE *fp; char str [30]; fgets (str,30,fp);
fputs( ) function is used for writing a string into a file.
The syntax for fputs() function is as follows −
fputs (string variable, file pointer);
For example,
FILE *fp; char str[30]; fputs (str,fp);
Program
Following is the C program for using fgets() and fputs() functions −
#include <stdio.h>
int main(){
FILE *fptr = fopen("sample.txt","w");
fputs("TutorialPoints\n",fptr);
fputs("C programming\n",fptr);
fputs("Question & Answers",fptr);
fclose(fptr);
fptr = fopen("sample.txt","r");
char string[30];
while(fgets(string,30,fptr)!=NULL){
printf("%s",string);
}
fclose(fptr);
return 0;
}Output
When the above program is executed, it produces the following result −
TutorialPoints C programming Question & Answers