Reading a File
To read a file there are following function available:
- Function fgetc(): Function fgetc() is used to read a single character at a time from the input file. The syntax of this function is −
Syntax :
int fgetc( FILE * fp );
- Functions fgets(): Functions fgets() is used to reads string from input file, one line at a time. The syntax of this function is –
Syntax :
char *fgets( char *buf, int n, FILE *fp );
function fgets() copies the read string into the buffer buf and appending a null character to terminate the string.
Here “n” is a size of buffer.
*fp- is a file pointer.
If the function fgets() encounters a character ‘\n’ ( newline ) or the end of the file ( EOF ) before reading the maximum number of characters, then it will returns the characters read up to that point including the new line character.
- Function fscan(): Function fscan() is also use to read strings from a file. The syntax of this function is –
Syntax :
int fscanf(FILE *fp, const char *format, …)
Note: fscan() function stops reading after encountering the first space character in file.
Closing a File
The fclose() function is used to
close an already opened file. The syntax of this function is −
Syntax :
int fclose( FILE *fp );
Function fclose(-) returns zero if the file is successfully closed, or EOF if there is an error in closing the file.
Example: Write a C program to show the use of fgets() and fscan() function using file handling.
Suppose we have a file Book.txt, that have following content
| Hello hii how are you I am aditya |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | #include <stdio.h> int main() { FILE *fp; char buff[250]; // 250 is a size of buffer fp = fopen("Book.txt", "r"); // open file "book.txt" for reed fscanf(fp, "%s", buff); // read one word and store in buffer printf("\n fscan() function print = %s", buff ); fgets(buff, 250, (FILE*)fp); // read remain line till end of line and store in buffer printf("\n fgets() function print = %s", buff ); fgets(buff, 250, (FILE*)fp); printf("\n fgets() function print = %s", buff ); // read complete one line and store in buffer fclose(fp); // close file "book.txt" } |
OUTPUT
1 2 3 | fscan() function print = Hello fgets() function print = hii how are you fgets() function print = I am aditya |
Description: fscanf() function read only “Hello” because after that, it encountered a space. fscan() function stops reading after encountering the first space character in file.
Function fgets() reads the remaining line till it encountered end of line. fgets() is reads string from input file, one line at a time.
Finally, the last fgets() reads the second line completely.
Example: Write a C program to open a file, read a file and close file using file handling.
Or
Example: Write a program to show the use of fgetc() function.
Note: Used for reads a single character from file. It returns EOF at the end of file.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | #include<stdio.h> void main( ) { FILE *fp; // file pointer char ch; fp = fopen("file1.c","r"); // file1 is name of the file to be open while ( 1 ) // condition is true { //read each character from a file and stored in the character variable ‘ch’. ch = fgetc ( fp ); if ( ch == EOF ) // checking EOF { break; // break & jump outside of loop } printf("%c",ch); } fclose (fp ); } |
OUTPUT
The content of the file “file1” will be printed.