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-rw-r--r--src/util.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..cb8c155
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,98 @@
+/**
+ * gammad -- Cooperative gamma server
+ * Copyright (C) 2016 Mattias Andrée (maandree@kth.se)
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "util.h"
+
+#include <sys/stat.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+
+
+/**
+ * Duplicate a memory segment
+ *
+ * @param src The memory segment, must not be `NULL`
+ * @param n The size of the memory segment, must not be zero
+ * @return The duplicate of the memory segment,
+ * `NULL` on error
+ */
+void* memdup(const void* src, size_t n)
+{
+ void* dest = malloc(n);
+ if (dest == NULL)
+ return NULL;
+ memcpy(dest, src, n);
+ return dest;
+}
+
+
+/**
+ * Read an entire file
+ *
+ * @param fd The file descriptor
+ * @param n Output for the size of the file
+ * @return The read content, plus a NUL byte at
+ * the end (not counted in `*n`)
+ */
+void* nread(int fd, size_t* n)
+{
+ size_t size = 32;
+ ssize_t got;
+ struct stat st;
+ char* buf = NULL;
+ char* new;
+ int saved_errno;
+
+ *n = 0;
+
+ if (!fstat(fd, &st))
+ size = st.st_size <= 0 ? 32 : (size_t)(st.st_size);
+
+ buf = malloc(size + 1);
+ if (buf == NULL)
+ return NULL;
+
+ for (;;)
+ {
+ if (*n == size)
+ {
+ new = realloc(buf, (size <<= 1) + 1);
+ if (new == NULL)
+ goto fail;
+ buf = new;
+ }
+
+ got = read(fd, buf + *n, size - *n);
+ if (got < 0)
+ goto fail;
+ if (got == 0)
+ break;
+ *n += (size_t)got;
+ }
+
+ buf[*n] = '\0';
+ return buf;
+ fail:
+ saved_errno = errno;
+ free(buf);
+ errno = saved_errno;
+ return NULL;
+}
+