bca 2nd Sem Notes -Opening modes of files

• UNIT-I (Array)

Definition

Declaration & initialization of 1D 

Accessing array elements

Displaying array elements

Sorting arrays

Arrays and function

Declaration & initialization of 1D

Accessing and Displaying

Memory representation of array [Row Major, Column Major]

Multidimensional array

UNIT-II (Pointers)

Definition

Declaration & initialization

Indirection operator

address of operator

pointer arithmetic

dynamic memory allocation

arrays and pointers

function and pointers

UNIT-III (Strings)

Definition

Declaration & initialization

standard library function strlen()

strlen(),strcpy(),   strcat() ,strcmp()

Implementation without using standard library functions

UNIT-IV (Structures)

Definition

Declaration & initialization

Accessing fields

structure operations

Nested structures

Union: Definition  declaration

Differentiate between Union and structure

UNIT-V                                  (C Preprocessor)

Definition
Macro substitution directives
File inclusion directives
Conditional compilation
Bitwise Operators
Shift operators
Masks
Bitfield

UNIT-VI                                (File Handling)

Definition of Files,
Opening modes of files
Standard function
fopen(), fclose(),               feof() fseek(),                     fewind()
Using text files
fgetc(), fputc(),               fscanf()

Program's in C

Opening modes of files

Various File Opening Modes:

The file is opened using fopen() function, while opening you can use any of the following mode as per the requirement.
Mode “r”: It is a read only mode, which means if the file is opened in r mode, it won’t allow you to write and modify content of it. When fopen() opens a file successfully then it returns the address of first character of the file, otherwise it returns NULL.

Mode “w”: It is a write only mode. The fopen() function creates a new file when the specified file doesn’t exist and if it fails to open file then it returns NULL.

Mode “a”: Using this mode Content can be appended at the end of an existing file. Like Mode “w”, fopen() creates a new file if it file doesn’t exist. On unsuccessful open it returns NULL.
File Pointer points to: last character of the file.

Mode “r+”: This mode is same as mode “r”; however you can perform various operations on the file opened in this mode. You are allowed to read, write and modify the content of file opened in “r+” mode.
File Pointer points to: First character of the file.

Mode “w+”: Same as mode “w” apart from operations, which can be performed; the file can be read, write and modified in this mode.

Mode “a+”: Same as mode “a”; you can read and append the data in the file, however content modification is not allowed in this mode.

Next TopicStandard function fopen(), fclose(), feof() fseek(), fewind()

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