fgetc(3) - f39

1fgetc(3)                   Library Functions Manual                   fgetc(3)
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NAME

6       fgetc, fgets, getc, getchar, ungetc - input of characters and strings
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LIBRARY

9       Standard C library (libc, -lc)
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SYNOPSIS

12       #include <stdio.h>
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14       int fgetc(FILE *stream);
15       int getc(FILE *stream);
16       int getchar(void);
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18       char *fgets(char s[restrict .size], int size, FILE *restrict stream);
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20       int ungetc(int c, FILE *stream);
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DESCRIPTION

23       fgetc()  reads  the next character from stream and returns it as an un‐
24       signed char cast to an int, or EOF on end of file or error.
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26       getc() is equivalent to fgetc() except that it may be implemented as  a
27       macro which evaluates stream more than once.
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29       getchar() is equivalent to getc(stdin).
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31       fgets()  reads in at most one less than size characters from stream and
32       stores them into the buffer pointed to by s.  Reading  stops  after  an
33       EOF  or a newline.  If a newline is read, it is stored into the buffer.
34       A terminating null byte ('\0') is stored after the  last  character  in
35       the buffer.
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37       ungetc()  pushes  c  back to stream, cast to unsigned char, where it is
38       available for subsequent read operations.  Pushed-back characters  will
39       be returned in reverse order; only one pushback is guaranteed.
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41       Calls  to the functions described here can be mixed with each other and
42       with calls to other input functions from the stdio library for the same
43       input stream.
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45       For nonlocking counterparts, see unlocked_stdio(3).
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RETURN VALUE

48       fgetc(), getc(), and getchar() return the character read as an unsigned
49       char cast to an int or EOF on end of file or error.
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51       fgets() returns s on success, and NULL on error or when end of file oc‐
52       curs while no characters have been read.
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54       ungetc() returns c on success, or EOF on error.
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ATTRIBUTES

57       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
58       tributes(7).
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60       ┌────────────────────────────────────────────┬───────────────┬─────────┐
61       │Interface                                   │ Attribute     │ Value   │
62       ├────────────────────────────────────────────┼───────────────┼─────────┤
63       │fgetc(), fgets(), getc(), getchar(),        │ Thread safety │ MT-Safe │
64       │ungetc()                                    │               │         │
65       └────────────────────────────────────────────┴───────────────┴─────────┘
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STANDARDS

68       C11, POSIX.1-2008.
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HISTORY

71       POSIX.1-2001, C89.
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NOTES

74       It  is  not  advisable  to  mix calls to input functions from the stdio
75       library with  low-level  calls  to  read(2)  for  the  file  descriptor
76       associated  with  the  input  stream; the results will be undefined and
77       very probably not what you want.
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