NAME

getc, getchar, fgetc, getw − get character or word from a stream

SYNOPSIS

#include <stdio.h>

int getc (FILE ∗stream);

int getchar (void);

int fgetc (FILE ∗stream);

int getw (FILE ∗stream);

DESCRIPTION

getc returns the next character (that is, byte) from the named input stream [see intro(3)] as an unsigned char converted to an int.  It also moves the file pointer, if defined, ahead one character in stream. getchar is defined as getc(stdin).  getc and getchar are macros. 

fgetc behaves like getc, but is a function rather than a macro.  fgetc runs more slowly than getc, but it takes less space per invocation and its name can be passed as an argument to a function. 

getw returns the next word (that is, integer) from the named input stream.  getw increments the associated file pointer, if defined, to point to the next word.  The size of a word is the size of an integer and varies from machine to machine.  getw assumes no special alignment in the file. 

SEE ALSO

fclose(3S), ferror(3S), fopen(3S), fread(3S), gets(3S), putc(3S), scanf(3S), stdio(3S), ungetc(3S)

DIAGNOSTICS

These functions return the constant EOF at end-of-file or upon an error and set the EOF or error indicator of stream, respectively.  Because EOF is a valid integer, ferror should be used to detect getw errors. 

NOTES

If the integer value returned by getc, getchar, or fgetc is stored into a character variable and then compared against the integer constant EOF, the comparison may never succeed, because sign-extension of a character on widening to integer is implementation dependent. 

The macro version of getc evaluates a stream argument more than once and may treat side effects incorrectly.  In particular, getc(∗f++) does not work sensibly.  Use fgetc instead. 

Because of possible differences in word length and byte ordering, files written using putw are implementation dependent, and may not be read using getw on a different processor. 

Functions exist for all the above-defined macros.  To get the function form, the macro name must be undefined (for example, #undef getc). 

  —  C Development Set