mirror of
https://github.com/mfocko/blog.git
synced 2024-12-23 21:01:29 +01:00
66 lines
3.6 KiB
Text
66 lines
3.6 KiB
Text
|
FGETC(3) Linux Programmer's Manual FGETC(3)
|
|||
|
|
|
|||
|
|
NAME
|
|||
|
|
fgetc, fgets, getc, getchar, ungetc - input of characters and strings
|
|||
|
|
|
|||
|
|
SYNOPSIS
|
|||
|
|
#include <stdio.h>
|
|||
|
|
|
|||
|
|
int fgetc(FILE *stream);
|
|||
|
|
|
|||
|
|
char *fgets(char *s, int size, FILE *stream);
|
|||
|
|
|
|||
|
|
int getc(FILE *stream);
|
|||
|
|
|
|||
|
|
int getchar(void);
|
|||
|
|
|
|||
|
|
int ungetc(int c, FILE *stream);
|
|||
|
|
|
|||
|
|
DESCRIPTION
|
|||
|
|
fgetc() reads the next character from stream and returns it as an unsigned char cast to an int, or EOF on end of file or error.
|
|||
|
|
|
|||
|
|
getc() is equivalent to fgetc() except that it may be implemented as a macro which evaluates stream more than once.
|
|||
|
|
|
|||
|
|
getchar() is equivalent to getc(stdin).
|
|||
|
|
|
|||
|
|
fgets() reads in at most one less than size characters from stream and stores them into the buffer pointed to by s. Reading stops after an EOF or a newline. If a newline is read, it is stored into the buf‐
|
|||
|
|
fer. A terminating null byte ('\0') is stored after the last character in the buffer.
|
|||
|
|
|
|||
|
|
ungetc() pushes c back to stream, cast to unsigned char, where it is available for subsequent read operations. Pushed-back characters will be returned in reverse order; only one pushback is guaranteed.
|
|||
|
|
|
|||
|
|
Calls to the functions described here can be mixed with each other and with calls to other input functions from the stdio library for the same input stream.
|
|||
|
|
|
|||
|
|
For nonlocking counterparts, see unlocked_stdio(3).
|
|||
|
|
|
|||
|
|
RETURN VALUE
|
|||
|
|
fgetc(), getc() and getchar() return the character read as an unsigned char cast to an int or EOF on end of file or error.
|
|||
|
|
|
|||
|
|
fgets() returns s on success, and NULL on error or when end of file occurs while no characters have been read.
|
|||
|
|
|
|||
|
|
ungetc() returns c on success, or EOF on error.
|
|||
|
|
|
|||
|
|
ATTRIBUTES
|
|||
|
|
For an explanation of the terms used in this section, see attributes(7).
|
|||
|
|
|
|||
|
|
┌──────────────────────────┬───────────────┬─────────┐
|
|||
|
|
│Interface │ Attribute │ Value │
|
|||
|
|
├──────────────────────────┼───────────────┼─────────┤
|
|||
|
|
│fgetc(), fgets(), getc(), │ Thread safety │ MT-Safe │
|
|||
|
|
│getchar(), ungetc() │ │ │
|
|||
|
|
└──────────────────────────┴───────────────┴─────────┘
|
|||
|
|
|
|||
|
|
CONFORMING TO
|
|||
|
|
POSIX.1-2001, POSIX.1-2008, C89, C99.
|
|||
|
|
|
|||
|
|
It is not advisable to mix calls to input functions from the stdio library with low-level calls to read(2) for the file descriptor associated with the input stream; the results will be undefined and very prob‐
|
|||
|
|
ably not what you want.
|
|||
|
|
|
|||
|
|
SEE ALSO
|
|||
|
|
read(2), write(2), ferror(3), fgetwc(3), fgetws(3), fopen(3), fread(3), fseek(3), getline(3), gets(3), getwchar(3), puts(3), scanf(3), ungetwc(3), unlocked_stdio(3), feature_test_macros(7)
|
|||
|
|
|
|||
|
|
COLOPHON
|
|||
|
|
This page is part of release 5.07 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at
|
|||
|
|
https://www.kernel.org/doc/man-pages/.
|
|||
|
|
|
|||
|
|
GNU 2017-09-15 FGETC(3)
|