Initial checkin of new os_compat.c source.

This file combines the code from clock_gettime.c, daemon.c, and strl.c
into a single "OS compatibility" module.  This initial version is just
a verbatim concatenation of those three sources, which is not yet
used.  Editing it for initial use is left to a separate commit for
easier tracking of the edits.

Since there's no "git cat" operation, the history of the code in this
file is not directly available in relation to this file, but can be
found in the histories of its three component sources (even after
their upcoming deletions).

TESTED:
Inapplicable.

1 files changed, 230 insertions, 0 deletions

diff --git a/os_compat.c b/os_compat.c
new file mode 100644
index 00000000..f7c23839
--- /dev/null
+++ b/os_compat.c
@@ -0,0 +1,230 @@
+/*
+ * Simulate ANSI/POSIX conformance on platforms that don't have it
+ *
+ * This file is Copyright (c) 2010 by the GPSD project
+ * BSD terms apply: see the file COPYING in the distribution root for details.
+ */
+
+#include <time.h>
+#include <sys/time.h>
+
+#include "compiler.h"
+
+#ifndef HAVE_CLOCK_GETTIME
+
+/*
+ * Note that previous versions of this code made use of clock_get_time()
+ * on OSX, as a way to get time of day with nanosecond resolution.  But
+ * it turns out that clock_get_time() only has microsecond resolution,
+ * in spite of the data format, and it's also substantially slower than
+ * gettimeofday().  Thus, it makes no sense to do anything special for OSX.
+ */
+
+int clock_gettime(clockid_t clk_id UNUSED, struct timespec *ts)
+{
+    struct timeval tv;
+    if (gettimeofday(&tv, NULL) < 0)
+	return -1;
+    ts->tv_sec = tv.tv_sec;
+    ts->tv_nsec = tv.tv_usec * 1000;
+    return 0;
+}
+#endif /* HAVE_CLOCK_GETTIME */
+
+/* end */
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "gpsd_config.h"
+#ifndef HAVE_DAEMON
+#if defined (HAVE_PATH_H)
+#include <paths.h>
+#else
+#if !defined (_PATH_DEVNULL)
+#define _PATH_DEVNULL    "/dev/null"
+#endif
+#endif
+
+int daemon(int nochdir, int noclose)
+/* compatible with the daemon(3) found on Linuxes and BSDs */
+{
+    int fd;
+
+    switch (fork()) {
+    case -1:
+	return -1;
+    case 0:			/* child side */
+	break;
+    default:			/* parent side */
+	exit(EXIT_SUCCESS);
+    }
+
+    if (setsid() == -1)
+	return -1;
+    if ((nochdir==0) && (chdir("/") == -1))
+	return -1;
+    if ((noclose==0) && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
+	(void)dup2(fd, STDIN_FILENO);
+	(void)dup2(fd, STDOUT_FILENO);
+	(void)dup2(fd, STDERR_FILENO);
+	if (fd > 2)
+	    (void)close(fd);
+    }
+    /* coverity[leaked_handle] Intentional handle duplication */
+    return 0;
+}
+
+#endif /* HAVE_DAEMON */
+
+// end
+/*
+ * This file is Copyright (c) 2010 by the GPSD project
+ * BSD terms apply: see the file COPYING in the distribution root for details.
+ */
+#include <string.h>
+#include <time.h>       /* for time_t */
+#include "gpsd_config.h"
+
+/*
+ * These versions use memcpy and strlen() because they are often
+ * heavily optimized down to assembler level. Thus, likely to be
+ * faster even with the function call overhead.
+ */
+
+#ifndef HAVE_STRLCAT
+/*
+ * Appends src to string dst of size siz (unlike strncat, siz is the
+ * full size of dst, not space left).  At most siz-1 characters
+ * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
+ * Returns strlen(src) + MIN(siz, strlen(initial dst)).
+ * If retval >= siz, truncation occurred.
+ */
+size_t strlcat(char *dst, const char *src, size_t siz)
+{
+    size_t slen = strlen(src);
+    size_t dlen = strlen(dst);
+    if (siz != 0) {
+	if (dlen + slen < siz)
+	    memcpy(dst + dlen, src, slen + 1);
+	else {
+	    memcpy(dst + dlen, src, siz - dlen - 1);
+	    dst[siz - 1] = '\0';
+	}
+    }
+    return dlen + slen;
+}
+
+#ifdef __UNUSED__
+/*	$OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie Exp $	*/
+
+/*
+ * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+size_t strlcat(char *dst, const char *src, size_t siz)
+{
+    char *d = dst;
+    const char *s = src;
+    size_t n = siz;
+    size_t dlen;
+
+    /* Find the end of dst and adjust bytes left but don't go past end */
+    while (n-- != 0 && *d != '\0')
+	d++;
+    dlen = (size_t) (d - dst);
+    n = siz - dlen;
+
+    if (n == 0)
+	return (dlen + strlen(s));
+    while (*s != '\0') {
+	if (n != 1) {
+	    *d++ = *s;
+	    n--;
+	}
+	s++;
+    }
+    *d = '\0';
+
+    return (dlen + (s - src));	/* count does not include NUL */
+}
+#endif /* __UNUSED__ */
+#endif /* HAVE_STRLCAT */
+
+#ifndef HAVE_STRLCPY
+/*
+ * Copy src to string dst of size siz.  At most siz-1 characters
+ * will be copied.  Always NUL terminates (unless siz == 0).
+ * Returns strlen(src); if retval >= siz, truncation occurred.
+ */
+size_t strlcpy(char *dst, const char *src, size_t siz)
+{
+    size_t len = strlen(src);
+    if (siz != 0) {
+	if (len >= siz) {
+	    memcpy(dst, src, siz - 1);
+	    dst[siz - 1] = '\0';
+	} else
+	    memcpy(dst, src, len + 1);
+    }
+    return len;
+}
+
+#ifdef __UNUSED__
+/*	$OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert Exp $	*/
+
+/*
+ * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+size_t strlcpy(char *dst, const char *src, size_t siz)
+{
+    char *d = dst;
+    const char *s = src;
+    size_t n = siz;
+
+    /* Copy as many bytes as will fit */
+    if (n != 0) {
+	while (--n != 0) {
+	    if ((*d++ = *s++) == '\0')
+		break;
+	}
+    }
+
+    /* Not enough room in dst, add NUL and traverse rest of src */
+    if (n == 0) {
+	if (siz != 0)
+	    *d = '\0';		/* NUL-terminate dst */
+	while (*s++ != '\0')
+	    continue;
+    }
+
+    return ((size_t) (s - src - 1));	/* count does not include NUL */
+}
+#endif /* __UNUSED__ */
+#endif /* HAVE_STRLCPY */