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 non-locking counterparts, see unlocked_stdio(3).
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28 fread() and fwrite() return the number of items successfully read or
29 written (i.e., not the number of characters). If an error occurs, or
30 the end-of-file is reached, the return value is a short item count (or
31 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 3.22 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 1996-05-17 FREAD(3)