33abc8bcd9
It wraps strlcpy(3bsd) so that it performs some steps that one might forget, or might be prone to accidents: - It calculates the size of the destination buffer, and makes sure it's an array (otherwise, using sizeof(dst) would be very bad). - It calculates if there's truncation, returning an easy-to-use value. BTW, this macro doesn't have any issues of double evaluation, because sizeof() doesn't evaluate its argument (unless it's a VLA, but then the static_assert(3) within SIZEOF_ARRAY() makes sure VLAs are not allowed). Cc: Christian Göttsche <cgzones@googlemail.com> Cc: Serge Hallyn <serge@hallyn.com> Cc: Iker Pedrosa <ipedrosa@redhat.com> Signed-off-by: Alejandro Colomar <alx@kernel.org>
57 lines
1.5 KiB
C
57 lines
1.5 KiB
C
/*
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* SPDX-FileCopyrightText: 2023, Alejandro Colomar <alx@kernel.org>
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#ifndef SHADOW_INCLUDE_LIB_STRLCPY_H_
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#define SHADOW_INCLUDE_LIB_STRLCPY_H_
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#include <config.h>
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#include <stddef.h>
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#include <string.h>
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#include "sizeof.h"
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/*
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* SYNOPSIS
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* int STRLCPY(char dst[restrict], const char *restrict src);
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*
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* ARGUMENTS
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* dst Destination buffer where to copy a string.
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* src Source string to be copied into dst.
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*
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* DESCRIPTION
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* This macro copies the string pointed to by src, into a string
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* at the buffer pointed to by dst. If the destination buffer,
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* isn't large enough to hold the copy, the resulting string is
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* truncated. The size of the buffer is calculated internally via
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* SIZEOF_ARRAY().
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*
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* RETURN VALUE
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* -1 If this call truncated the resulting string.
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*
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* strlen(dst)
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* On success.
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*
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* ERRORS
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* This function doesn't set errno.
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*/
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#define STRLCPY(dst, src) \
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({ \
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size_t sz_, len_; \
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\
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sz_ = SIZEOF_ARRAY(dst); \
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len_ = strlcpy(dst, src, sz_); \
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\
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(len_ >= sz_) ? -1 : len_; \
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})
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#endif // include guard
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