68 lines
2.2 KiB
C
68 lines
2.2 KiB
C
/* io.c - light wrappers for POSIX i/o functions
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* Time-stamp: <2010-11-13 08:22:53 njk>
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*
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* (c) 2010 Nicholas J. Kain <njkain at gmail dot com>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* - Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <unistd.h>
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#include <errno.h>
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/* returns -1 on error, >= 0 and equal to # chars read on success */
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int safe_read(int fd, char *buf, int len)
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{
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int r, s = 0;
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while (s < len) {
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r = read(fd, buf + s, len - s);
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if (r == 0)
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break;
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if (r == -1) {
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if (errno == EINTR)
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continue;
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else
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return -1;
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}
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s += r;
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}
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return s;
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}
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/* returns -1 on error, >= 0 and equal to # chars written on success */
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int safe_write(int fd, const char *buf, int len)
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{
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int r, s = 0;
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while (s < len) {
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r = write(fd, buf + s, len - s);
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if (r == -1) {
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if (errno == EINTR)
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continue;
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else
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return -1;
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}
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s += r;
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}
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return s;
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}
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