C library function - fprintf() (2024)

FAQs

C library function - fprintf()? ›

fprintf() -- Write Formatted Data to a Stream

C has a library function fprintf, also known as the format print function, that sends formatted output string to a stream. The fprintf in C is used to write data in a file using a stream object, not in the stdout console.

Writing File : fprintf() function

The fprintf() function is used to write set of characters into file. It sends formatted output to a stream. Syntax: int fprintf(FILE *stream, const char *format [, argument, ...])

printf is a C function belonging to the ANSI C standard library, and included in the file stdio. h. Its purpose is to print formatted text to the standard output stream. Hence the "f" in the name stands for "formatted".

The difference between printf and fprintf is that printf is used to print a formatted string to a standard output which is most of the time a computer screen and fprintf is used to print a formatted string to a specific file.

All C standard library functions are declared by using many header files. These library functions are created at the time of designing the compilers. All the header files should have a ". h" extension.

In C language, printf() function is used to print formatted output to the standard output stdout (which is generally the console screen). The printf function is a part of the C standard library <stdio. h> and it can allow formatting the output in numerous ways.

The fprintf function allows you to "write" information to the screen for the user to view. This very important when user interaction is involved. The 'f' in printf stands for formatted. This means you can "format" how the data is printed in such a manner as to make it easy to read.

The fprintf() function is similar to printf() , but writes its output to the stream specified by fp rather than to stdout .

Difference between fwrite() and fprintf()?

So if you pass a pointer to an integer to fwrite , it writes the bytes of the integer into the file just as they are represented in RAM. fprintf prints according to a formatting string where you can specify how the data is supposed to be formatted.

How to use printf function in C? ›

Basic Printf Examples

Displaying a simple message: printf("Hello, world!"); This example displays a simple message. The output will be: "Hello, world!" 2. Displaying an integer: int number = 42; printf("The answer is: %d", number);

The two PRINT procedures perform formatted output. PRINT performs output to the standard output stream (IDL file unit -1), while PRINTF requires a file unit to be explicitly specified. Note: IDL uses the standard I/O function sprintf to do its formatting.

h header file is also part of the standard C library and contains declarations for input and output functions like scanf() , printf() , and others. To use the scanf() function in a C program, you need to include the stdio. h header file at the beginning of your program using the #include preprocessor directive.

The function fprintf() is known as format print function. It writes and formats the output to a stream. It is used to print the message but not on stdout console. Here is the syntax of fprintf() in C language, int fprintf(FILE *fptr, const char *str, ... );

printf() is perfect for fast and simple console printing, while fprintf() enables file output and robust error handling.

Typically use fprintf() for all output statements in your program that produce problem specific output. Typically use disp() only when you are debugging for "quick and dirty" output to help find errors. When you are not sure what precision a computed value will have, display it with the %g format descriptor.

One commonly used function in the standard C library is sprintf() , which is used to format a string with variables. This also includes variations like snprintf() and also functions that call snprintf() internally, like Log.info() and String::format() .

gets is a function in the C standard library, declared in the header file stdio. h , that reads a line from the standard input and stores it in a buffer provided by the caller.

The system() function is a part of the C/C++ standard library. It is used to pass the commands that can be executed in the command processor or the terminal of the operating system, and finally returns the command after it has been completed. <stdlib.

Libaries consist of a set of related functions to perform a common task; for example, the standard C library, 'libc. a', is automatically linked into your programs by the “gcc” compiler and can be found at /usr/lib/libc. a. Standard system libraries are usually found in /lib and /usr/lib/ directories.