1FREAD(3) Linux Programmer's Manual FREAD(3)
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6 fread, fwrite - binary stream input/output
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9 #include <stdio.h>
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11 size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream);
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13 size_t fwrite(const void *ptr, size_t size, size_t nmemb,
14 FILE *stream);
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17 The function fread() reads nmemb elements of data, each size bytes
18 long, from the stream pointed to by stream, storing them at the loca‐
19 tion given by ptr.
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21 The function fwrite() writes nmemb elements of data, each size bytes
22 long, to the stream pointed to by stream, obtaining them from the loca‐
23 tion given by ptr.
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25 For nonlocking counterparts, see unlocked_stdio(3).
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28 On success, fread() and fwrite() return the number of items read or
29 written. This number equals the number of bytes transferred only when
30 size is 1. If an error occurs, or the end of the file is reached, the
31 return value is a short item count (or zero).
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33 fread() does not distinguish between end-of-file and error, and callers
34 must use feof(3) and ferror(3) to determine which occurred.
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37 C89, POSIX.1-2001.
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40 read(2), write(2), feof(3), ferror(3), unlocked_stdio(3)
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43 This page is part of release 3.53 of the Linux man-pages project. A
44 description of the project, and information about reporting bugs, can
45 be found at http://www.kernel.org/doc/man-pages/.
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49GNU 2012-03-30 FREAD(3)