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65 lines
3.6 KiB
Text
65 lines
3.6 KiB
Text
FGETC(3) Linux Programmer's Manual FGETC(3)
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NAME
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fgetc, fgets, getc, getchar, ungetc - input of characters and strings
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SYNOPSIS
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#include <stdio.h>
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int fgetc(FILE *stream);
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char *fgets(char *s, int size, FILE *stream);
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int getc(FILE *stream);
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int getchar(void);
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int ungetc(int c, FILE *stream);
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DESCRIPTION
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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.
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getc() is equivalent to fgetc() except that it may be implemented as a macro which evaluates stream more than once.
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getchar() is equivalent to getc(stdin).
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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‐
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fer. A terminating null byte ('\0') is stored after the last character in the buffer.
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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.
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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.
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For nonlocking counterparts, see unlocked_stdio(3).
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RETURN VALUE
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fgetc(), getc() and getchar() return the character read as an unsigned char cast to an int or EOF on end of file or error.
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fgets() returns s on success, and NULL on error or when end of file occurs while no characters have been read.
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ungetc() returns c on success, or EOF on error.
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ATTRIBUTES
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For an explanation of the terms used in this section, see attributes(7).
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┌──────────────────────────┬───────────────┬─────────┐
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│Interface │ Attribute │ Value │
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├──────────────────────────┼───────────────┼─────────┤
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│fgetc(), fgets(), getc(), │ Thread safety │ MT-Safe │
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│getchar(), ungetc() │ │ │
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└──────────────────────────┴───────────────┴─────────┘
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CONFORMING TO
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POSIX.1-2001, POSIX.1-2008, C89, C99.
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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‐
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ably not what you want.
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SEE ALSO
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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)
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COLOPHON
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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
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https://www.kernel.org/doc/man-pages/.
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GNU 2017-09-15 FGETC(3)
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