File Handling

1. File Handling Summer 2014 COMP 2130 Intro Computer Systems Computing Science Thompson Rivers University

2. Your vision? Seek with all your heart? Unit Learning Objectives • Explain the concept pf data files • Explain different types of files Code Optimization

3. Types of Files • Three categories of files • Text files • Formatted files • Binary files Introduction

4. Common Functions • Define a File pointer • FILE *fp • Open a File • Fopen(“filename, “mode” • R, w, a, r+, w+, a+ • Close a File • Fclose(fp) • Perform operations • Fscanf() • fprintf() • Fgetc() • Fputc() Introduction

5. Create a file #include <stdio.h> main() { FILE *fp; fp= fopen(“test.txt", "w+"); fprintf(fp, "This is testing for fprintf...\n"); fputs("This is testing for fputs...\n", fp); fputc(ch, fp); fclose(fp); } Introduction

6. Read a file int main () { FILE *fp; int c; fp= fopen("file.txt","r"); while(1) { c = fgetc(fp); if( feof(fp) ) { break ; } printf("%c", c); } fclose(fp); return(0); } Introduction

7. Merging command line arguments /* fgetsexmaple */ #include <stdio.h> intmain(intarg, char *argv[]) { FILE * pFile; char string [BUFSIZ]; pFile = fopen (argv[1] , "r"); if (pFile == NULL) perror ("Error opening file"); else { while (fgets (string , BUFSIZ, pFile) != NULL) { puts (string); } fclose (pFile); } return 0; } Introduction