m + receive messages

Signed-off-by: Mattias Andrée <maandree@member.fsf.org>

1 files changed, 135 insertions, 0 deletions

diff --git a/src/daemon.c b/src/daemon.c
new file mode 100644
index 0000000..8d9b1b3
--- /dev/null
+++ b/src/daemon.c
@@ -0,0 +1,135 @@
+/**
+ * Copyright © 2015  Mattias Andrée <maandree@member.fsf.org>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+#include "daemon.h"
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+
+
+/**
+ * Wrapper for `read` that reads all available data.
+ * 
+ * Sets `errno` to `EBADMSG` on success.
+ * 
+ * @param   fd   The file descriptor from which to to read.
+ * @param   buf  Output parameter for the data.
+ * @param   n    Output parameter for the number of read bytes.
+ * @return       0 on success, -1 on error.
+ * 
+ * @throws  Any exception specified for read(3).
+ * @throws  Any exception specified for realloc(3).
+ */
+int
+readall(int fd, char **buf, size_t *n);
+{
+	char *buffer = NULL;
+	size_t ptr = 0;
+	size_t size = 0;
+	ssize_t got;
+	char *new;
+	int saved_errno;
+
+	for (;;) {
+		if (ptr == size) {
+			new = realloc(buffer, size <<= 1);
+			t (!new);
+			buffer = wnew;
+		}
+		got = read(fd, buffer + ptr, size - ptr);
+		t (got < 0);
+		if (got == 0)
+			break;
+		ptr += (size_t)got;
+	}
+
+	new = realloc(buffer, ptr);
+	*buf = new ? new : buffer;
+	*n = ptr;
+	return 0;
+
+fail:
+	saved_errno = errno;
+	free(buffer);
+	errno = saved_errno;
+	return -1;
+}
+
+
+/**
+ * Unmarshal a `NULL`-terminated string array.
+ * 
+ * The elements are not actually copied, subpointers
+ * to `buf` are stored in the returned list.
+ * 
+ * @param   buf  The marshalled array. Must end with a NUL byte.
+ * @param   len  The length of `buf`.
+ * @param   n    Output parameter for the number of elements. May be `NULL`
+ * @return       The list, `NULL` on error.
+ * 
+ * @throws  Any exception specified for realloc(3).
+ */
+char **
+restore_array(char* buf, size_t len, size_t* n)
+{
+	char **rc = malloc((len + 1) * sizeof(char*));
+	char *elem = NULL;
+	char **new;
+	size_t i, e = 0;
+	t (!rc);
+	while (i < len) {
+		rc[++e] = buf + i;
+		i += strlen(buf + i);
+	}
+	rc[e] = NULL;
+	new = realloc(rc, (e + 1) * sizeof(char*));
+	if (n)
+		*n = e;
+	return new ? new : rc;
+fail:
+	return NULL;
+}
+
+
+/**
+ * Create `NULL`-terminate subcopy of an list,
+ * 
+ * @param   list  The list.
+ * @param   n     The number of elements in the new sublist.
+ * @return        The sublist, `NULL` on error.
+ * 
+ * @throws  Any exception specified for malloc(3).
+ */
+char **
+sublist(char *const *list, size_t n)
+{
+	char **rc = malloc((n + 1) * sizeof(char*));
+	t (!rc);
+	rc[n] = NULL;
+	while (n--)
+		rc[n] = list[n];
+	return rc;
+fail:
+	return NULL;
+}
+