File Management
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This document discusses file management in C programming. It introduces file input/output (I/O) functions that allow reading from and writing to files, such as fopen(), fclose(), getc(), putc(), fprintf(), and fscanf(). These functions open, close, read/write single characters and integers from files. The document also covers error handling during file I/O operations and using functions like fseek(), ftell(), and rewind() for random file access. It concludes with a brief discussion of command line arguments.
File Management
- 1. Cpu(2110003) Group Project β12.File Managementβ Branch : Mech I-3 Prepared By: Jani Parth U.(150120119051) Jerin Sibi.(150120119052) Joshi Parth.(150120119053) Guided By: Prof. Raxit Jani
- 2. INTRODUCTION ο΅ Until Now We Have Been Using The Function Such As Scanf And Printf To Read And Write Data. These Are Console Oriented I/O Functions, Which Always Use The Terminal As The Target. ο΅ The Console Oriented I/O Pose Two Major Problem: 1. It Becomes Complex And Time Consuming To Handle Large Volume Of Data Through Terminal. 2. The Entire Data Is Lost When Either The Program Is Terminated.
- 3. ο΅A File Is A Place On The Disk Where A Group Of Related Data Is Stored. Like Other Language C Supports A Number Of Function That Has The Ability To Perform Basic File Operation, Which Include: 1. Naming A File 2. Opening A File 3. Reading Data 4. Writing Data 5. Closing A File
- 4. FUNCTION NAME OPERATION ο fopen() οΌ Creates a new file for use. ο fclose() οΌ Close a file which is open for use. ο getc() οΌ Reads a character from file. ο putc() οΌ Writes a character to a file. ο fprint() οΌ Writes a set of data values to the file. ο fscanf() οΌ Reads a set of data value from a file. ο getw() οΌ Read an integer from the file. HIGH LEVEL I/O FUNCTION
- 5. DEFINING AND OPENING A FILE οIf we want to store data in a file in the secondary memory, we must specify certain things about the file. They include: 1) FILENAME 2) DATA STRUCTURE 3) PURPOSE ο΅DATA STRUCTURE OF A FILE IS DEFINED AS FILE. FOLLOWING is the general format for declaring and opening a file. ο΅ FILE *fp; ο΅ fp = fopen(βfilenameβ , βmodeβ);
- 6. CLOSING A FILE ο΅A file must be closed as soon as operation on it have been completed. Another instance where we have to close a file is when we want to reopen it. ο΅The I/O library supports a function to do this for us. It takes the following forms: fclose(file_ pointer);
- 7. GETC AND PUTC FUNCTION ο΅ The simplest file I/O functions are getc and putc. These are the getchar and putchar functions and handle one character at a time. The statement: putc(c , fp1); ο΅ Similarly, getc is used to read the character from a file that has been opened in read mode. The statement: c= getc(fp2) ;
- 8. GETW AND PUTW FUNCTION ο΅The getw and putw are integer-oriented functions. They are similar to the getc and putc functions and are used to read and write integer values. The general form are: putw(integer ,fp); getw(fp);
- 9. THE fprintf and fscanf FUNCTION ο The function fprintf and fscanf perform I/O operation that are identical to the familiar printf and scanf functions, except of course that they work on files. The general form: fprintf(fp , βcontrol stringsβ ,list); ο The list may include constant, variable and strings. The general format of fscanf is: fprintf(fp , βcontrol stringsβ ,list);
- 10. ERROR HANDLING DURING I/O OPERATOR ο΅It is possible an error may occur during I/O operation on a file. They are: 1) Trying to read beyond the end- of- line mark. 2) Device overflow 3) Trying to use a file that has not been opened. 4) Trying to perform an operation on a file, when the file is opened for another type of operation. 5) Opening a file with an invalid filename. 6) Attempting to write to a write-protected file.
- 11. RANDOM ACESS TO FILE ο΅It can be achieved with the help of the functions fseek, ftell, and rewind available in the I/O library. ο΅Ftell takes a file pointer and return a number of type long, that corresponds to the current position. n = ftell(fp); ο΅Rewind takes a file pointer and resets the position to the start of the file. rewind(fp); n = ftell(fp); ο΅fseek function is used to move the file position to a desired location within the file. fseek(file_ ptr , offset, position);
- 12. COMMAND LINE ARGUMENT ο΅ Itβs a parameter supplied to a program when the program is invoked. For example , if we want to copy the contents of a file X_FILE to another named Y_FILE, then: C > PROGRAM X_ FILE Y_ FILE ο΅ Where PROGRAM is the filename where the executable code of the program is stored.