File Input Output — Part 1 MCQs with Explanations

The correct answer is A: getc() Let's break down why: getc() is a standard C library function specifically designed to read a single character from a file stream. It takes a file pointer (FILE*) as an argument and returns the character read (as an integer) or EOF if the end of the file is reached or an error occurs. readchar() is not a standard C function for file input. read() is a lower-level function (usually from the POSIX standard) used for reading a block of data from a file descriptor, not a single character. getchar() reads a character from standard input (stdin), which is usually the keyboard, not from a file. So, getc() is the correct function to use when you want to read a single character from a file in C.

FILE is a pre-defined structure.

Besides the file pointers which we explicitly open by calling fopen, there are also three predefined streams. stdin is a constant file pointer corresponding to standard input, and stdout is a constant file pointer corresponding to standard output. Both of these can be used anywhere when a file pointer is called for; for example, getchar() is the same as getc(stdin) and putchar(c) is the same as putc(c, stdout). The third predefined stream is stderr. Like stdout, stderr is typically connected to the screen by default. The difference is that stderr is not redirected when the standard output is redirected.

stdio.h is the correct answer to “In C, which library is used for file operations such as reading and writing files”. This question is standard in competitive examination syllabi for File Input Output.

fopen() is the correct answer to “Which function is used to open a file in C for writing”. This question is standard in competitive examination syllabi for File Input Output.

A file structure is the correct answer to “What does 'FILE' represent in C when working with files”. This question is standard in competitive examination syllabi for File Input Output.

Check the return value of fopen() is the correct answer to “How do you check if a file was opened successfully in C”. This question is standard in competitive examination syllabi for File Input Output.

fwrite() is the correct answer to “Which function is used to write data to a file in C”. This question is standard in competitive examination syllabi for File Input Output.

'r' is for reading and 'w' is for writing, overwriting an existing file is the correct answer to “What is the difference between 'r' and 'w' modes when opening a file in C”. This question is standard in competitive examination syllabi for File Input Output.

To format and write data to a file is the correct answer to “What is the purpose of the 'fprintf' function in C”. This question is standard in competitive examination syllabi for File Input Output.

fclose() is the correct answer to “Which function is used to close a file in C”. This question is standard in competitive examination syllabi for File Input Output.

To check if the file has reached the end is the correct answer to “In C, what is the function of the 'feof' function”. This question is standard in competitive examination syllabi for File Input Output.

fseek() is the correct answer to “Which function is used to move the file pointer to a specific position in a file”. This question is standard in competitive examination syllabi for File Input Output.

To reset the file pointer to the beginning is the correct answer to “What is the purpose of the 'rewind' function in C”. This question is standard in competitive examination syllabi for File Input Output.

fgets() is the correct answer to “Which function is used to read a line of text from a file in C”. This question is standard in competitive examination syllabi for File Input Output.

Reads binary data from a file is the correct answer to “What does the 'fread' function in C do”. This question is standard in competitive examination syllabi for File Input Output.

rename() is the correct answer to “Which function is used to rename a file in C”. This question is standard in competitive examination syllabi for File Input Output.

EOF is the correct answer to “In C, what does the 'feof' function return if the end of the file is reached”. This question is standard in competitive examination syllabi for File Input Output.

Check the return value of fopen() is the correct answer to “How do you check if a file exists in C”. This question is standard in competitive examination syllabi for File Input Output.

To find the current position of the file pointer is the correct answer to “What is the purpose of the 'ftell' function in C”. This question is standard in competitive examination syllabi for File Input Output.

putc() is the correct answer to “Which function is used to write a character to a file in C”. This question is standard in competitive examination syllabi for File Input Output.

An error occurs, and the file remains unchanged is the correct answer to “What happens if you try to open a file in 'r' mode that doesn't exist in C”. This question is standard in competitive examination syllabi for File Input Output.

fgets() is the correct answer to “How do you read a string from a file in C”. This question is standard in competitive examination syllabi for File Input Output.

Deletes a file is the correct answer to “What does the 'remove' function in C do”. This question is standard in competitive examination syllabi for File Input Output.

To flush the standard output buffer is the correct answer to “In C, what is the purpose of the 'fflush' function”. This question is standard in competitive examination syllabi for File Input Output.

mkdir() is the correct answer to “Which function is used to create a new directory in C”. This question is standard in competitive examination syllabi for File Input Output.

fprintf() is the correct answer to “How do you write an integer to a file in C”. This question is standard in competitive examination syllabi for File Input Output.

EOF is the correct answer to “What is the return value of 'putc' if it fails to write a character to a file in C”. This question is standard in competitive examination syllabi for File Input Output.

fread() is the correct answer to “Which function is used to read and write data in binary mode in C”. This question is standard in competitive examination syllabi for File Input Output.

To find the file number associated with a file is the correct answer to “What is the purpose of the 'fileno' function in C”. This question is standard in competitive examination syllabi for File Input Output.

When the output is to be printed on to a file. is the correct answer to “The function fprintf is used in the program ...........”. This question is standard in competitive examination syllabi for File Input Output.

fopen(filename, "r") is the correct answer to “Which one of the following is valid for opening a read-only ASCII file”. This question is standard in competitive examination syllabi for File Input Output.

if it is a macro, it may evaluate stream more than once is the correct answer to “Choose the correct difference between getc() and fgetc().”. This question is standard in competitive examination syllabi for File Input Output.

width is the correct answer to “. . . . . . . . is an optional argument that gives the maximum number of characters to be read.”. This question is standard in competitive examination syllabi for File Input Output.

Somegarbage value is the correct answer to “What will be the output of the following C code? #include <stdio.h> struct p { struct p *next; int x; }; int main() { struct p* p1 = malloc(sizeof(struct p)); p1->x = 1; p1->next = malloc(sizeof(struct p)); printf("%d\n", p1->next->x); return 0; }”. This question is standard in competitive examination syllabi for File Input Output.

A pointer to short is the correct answer to “If the conversion characters of int d, i, o, u and x are preceded by h, it indicates”. This question is standard in competitive examination syllabi for File Input Output.

srand(x) is the correct answer to “Which among the following mathematical function do not have a "double" return-type”. This question is standard in competitive examination syllabi for File Input Output.

strcasecmp(s, t) is the correct answer to “Which of the following function compares 2 strings with case-insensitively”. This question is standard in competitive examination syllabi for File Input Output.

It is a type name defined in stdio.h is the correct answer to “What is FILE reserved word”. This question is standard in competitive examination syllabi for File Input Output.

None of the mentioned is the correct answer to “What will be the output of the following C code? #include <stdio.h> #include <math.h> int main() { unsigned int i = -1; printf("%f\n", fabs(i)); return 0; }”. This question is standard in competitive examination syllabi for File Input Output.