Search results
Results From The WOW.Com Content Network
An example of the printf function. printf is a C standard library function that formats text and writes it to standard output. The name, printf is short for print formatted where print refers to output to a printer although the functions are not limited to printer output. The standard library provides many other similar functions that form a ...
For example, an integer can be printed using the "%d" formatting code, e.g.: printf("%d", 42); This formats the integer "42" as text and prints it to the standard output. printf is typically the first function any C programmer encounters, because it is the only function which appears in the standard Hello world program:
In Unix and Unix-like operating systems, printf is a shell builtin (and utility program [2]) that formats and outputs text like the same-named C function. Originally named for outputting to a printer, it actually outputs to standard output. [3] The command accepts a format string, which specifies how to format values, and a list of values.
In the above example, the main( ) function defines where the program should start executing. The function body consists of a single statement, a call to the printf() function, which stands for "print formatted"; it outputs to the console whatever is passed to it as the parameter, in this case the string "hello, world".
The next line of the program is a statement that calls (i.e. diverts execution to) a function named printf, which in this case is supplied from a system library. In this call, the printf function is passed (i.e. provided with) a single argument, which is the address of the first character in the string literal "hello, world\n".
The C standard library, sometimes referred to as libc, [1] is the standard library for the C programming language, as specified in the ISO C standard. [2] Starting from the original ANSI C standard, it was developed at the same time as the C POSIX library, which is a superset of it. [3]
The C programming language provides many standard library functions for file input and output.These functions make up the bulk of the C standard library header <stdio.h>. [1] The functionality descends from a "portable I/O package" written by Mike Lesk at Bell Labs in the early 1970s, [2] and officially became part of the Unix operating system in Version 7.
For example, ADD(VALUE, 2) expands to 1 / 12 + 2. Variadic. A variadic macro (introduced with C99) accepts a varying number of arguments which is particularly useful when wrapping functions that accept a variable number of parameters, such as printf. Order of expansion. Function-like macro expansion occurs in the following stages: