COP 3223C FINAL EXAM

#include

-#include <stdio.h> -inserts a particular header from another file - tell the CPP to get stdio.h from the system libraries and add the text to the current source file

a access mode

-opens a text file for writing in appending mode -if one doesn't exist, it will create a new one -program will start appending content in the existing file content

fgetc()

-reads a character from the input file referenced to by fp -returns the character read if success, EOF if error

fgets()

-reads up to n-1 characters from the input stream referenced to by fp -copies the read string into the buffer (buf), appending the null character to terminate the string

#

-stringsize operator -used within macro definition, converting a parameter into a string constant

all CPP begin with

# symbol -must be the first non blank character and for readability, a CPP directive should begin in the first column

#define

#define MAX_ARRAY_LENGTH 20 -substitutes a PP macro -tells the CPP to replace instances of MAX_ARRAY_LENGTH with 20 -use for constants to improve readability

#elif

#else and #if in one statement

#ifdef

#ifdef DEBUG -returns true if the macro is defined

#ifndef

#ifndef MESSAGE -returns true if the macro is not defined

#undef

#undef FILE_SIZE -undefines a PP macro

whats the difference between enum and macro

- follow scope rules - variables are automatically assigned values

parameters for fseek()

-1st: stream is the pointer to the file- -2nd: position of the record to be found -3rd: specifies the location where the offset starts

fwrite takes 4 arguments

-address of data to be written in disk -size of data to be written in disk -number of such type of data -pointer to the file where you want to write

errno

-global variable -indicated an error occurred during any function call

\

-macro continuation operator -continues a macro onto another line

C preprocessor

-not a part of the compiler, but a separate step in the compilation process -just a text substitution tool

a+ access mode

-opens a file for both reading and writing -creates a file if it does not exist -reading will start from the beginning but writing can only be appended

w+ access mode

-opens a text file for both reading and writing -first truncates the file to 0 length if it exists, otherwise creates a file if it does not exist.

w access mode

-opens a text file for writing -if one doesn't exist it will create a new one

how many access mode values are there?

6

#endif

ends preprocessor conditional

2 types of conversions

explicit (cast operator) and implicit (automatically done by compiler)

usual arithmetic conversions

first- integer promotion, if operands are still different types, then converted to type that appears highest in hierarchy

fread prototype

fread( address_data, size_data, numbers_data, pointer_to_file);

getting data using fseek()

fseek(FILE * stream, long int offset, int whence) -seeks the cursor to the given record in file

fwrite prototype

fwrite( address_data, size_data, numbers_data, pointer_to_file);

fclose() prototype

int fclose( FILE *fp );

simplest function to read a single character from a file

int fgetc( FILE * fp);

alternative for writing a string into a file

int fprintf(FILE *fp, const char *format, ....);

simplest function to write individual characters to a file

int fputc (int c, FILE *fp);

writing a null terminated string to a steream

int fputs( const char *s, FILE *fp);

reading a string from a file, but stopping after encountering the first space character)

int fscanf(FILE *fp, const char *format, ...)

parameterized macros

int square( int x) { return x*x; } can be rewritten as #define square(x) ((x) * (x))

#error

prints error message on stderr

integer promotion

process of converting values of int type 'smaller' than int or unsigned int are converted to int or unsigned int

__DATE__

returns the current date as a character literal in "MMM DD YYY" format

__TIME__

returns the current time as a character literal in "HH:MM:SS" format

access modes for opening binary files

same as the access modes for text files but with an added 'b' rb wb ab ...

What does a file represent?

sequence of bytes (regardless of it being a text file or a binary file)

##

-token pasting operator -within a macro definition combines 2 arguments

the defined() operator

-used in constant expressions to determine if an identifier is defined using #define -if defined: true: non-0 -if not defined: false: 0

fputc()

-writes the character value of the argument c to the output stream referenced by fp -returns the written character written on success, otherwise EOF if error

fputs()

-writes the string s to the output stream referenced to by fp -returns non negative value on success otherwise EOF if error

if we do not explicitly assign values to enum names, then the compiler assigned values starting from what number

0

fopen prototype

FILE *fopen( const char * filename, const char *mode);

C Programming provides access to what?

High and low (OS) level functions to handle file on storage devices.

EOF

a constant defined in the header file of stdio.h

usual arithmetic conversions are not performed for

assignment operators not logical operators && and ||

convert values from one type to another explicitly using

cast operator -(typename) expression

reading a string from a stream

char *fgets( char *buf, int n, FILE *fp);

fclose()

closing a file -returns 0 upon success or EOF if there is an error in closing -flushes any data still pending in the buffer, closes the file, then releases memory used for the file

__FILE__

contains the current file name as a string literal

__LINE__

contains the current line number as a decimal constant

type casting

converting a variable from one data type to another type

fopen()

create (and initialize) a new file or open an existing file

__STDC__

defined as 1 when the compiler compiles with the ANSI standard

perror()

displays the string you pass to it, followed by a colon, a space, and then the textual representation

#pragma

issues special command to the compiler using a standardized method

if fgets() encounters a new line character or EOF before reading the max number of characters

it returns only the characters read up to that point including the new line character

r+ access mode

opens a text file for both reading and writing

r access mode

opens an existing text file for reading purposes only

SEEK_SET whence in fseek()

starts the offset from the beginning of the file

SEEK_CUR whence in fseek()

starts the offset from the current location of the cursor in the file

SEEK_END whence in fseek()

starts the offset from the end of the file

#if

tests if a compile time condition is true

#else

the alternative of #if

what are enumerations mainly used for

to assign names to integral constants

all enum constants must be unique in their scope true/false

true

c programming does not provide direct support for error handling true/false

true

enumeration is a user defined data type true/false

true

two enum names can have the same value true/false

true

fread() & fwrite()

used for reading from and writing to a file on the disk respectively in case of binary files

A value of _____ indicates that there is no error in the program

zero