From e5aaa1a1401f5cc39b1816608b69d41237f2a689 Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@systemlinux.org>
Date: Tue, 27 May 2008 01:25:52 +0200
Subject: [PATCH] Add missing functions to fd.c.

These were previously exported by osl but don't really belong there.
---
 Makefile |   2 +-
 fd.c     | 141 ++++++++++++++++++++++++++++++++++++++++---------------
 fd.h     |   1 +
 3 files changed, 104 insertions(+), 40 deletions(-)

diff --git a/Makefile b/Makefile
index b590b29..ef94fcc 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-objects := adu.o string.o cmdline.o
+objects := adu.o string.o cmdline.o fd.o
 all: adu
 
 DEBUG_CPPFLAGS += -Wno-sign-compare -g -Wunused -Wundef -W
diff --git a/fd.c b/fd.c
index cfef4d9..7040b87 100644
--- a/fd.c
+++ b/fd.c
@@ -16,30 +16,116 @@
 #include "error.h"
 
 /**
- * Write a buffer to a file descriptor, re-write on short writes.
+ * Wrapper for the write system call.
  *
- * \param fd The file descriptor.
- * \param buf The buffer to be sent.
- * \param len The length of \a buf.
+ * \param fd The file descriptor to write to.
+ * \param buf The buffer to write.
+ * \param size The length of \a buf in bytes.
+ *
+ * This function writes out the given buffer and retries if an interrupt
+ * occurred during the write.
+ *
+ * \return On success, the number of bytes written is returned, otherwise, the
+ * function returns \p -E_WRITE.
  *
- * \return Standard. In any case, the number of bytes that have been written is
- * stored in \a len.
+ * \sa write(2).
  */
-int write_all(int fd, const char *buf, size_t *len)
+ssize_t para_write(int fd, const void *buf, size_t size)
 {
-	size_t total = *len;
-
-	assert(total);
-	*len = 0;
-	while (*len < total) {
-		int ret = write(fd, buf + *len, total - *len);
-		if (ret == -1)
-			return -ERRNO_TO_ERROR(errno);
-		*len += ret;
+	ssize_t ret;
+
+	for (;;) {
+		ret = write(fd, buf, size);
+		if ((ret < 0) && (errno == EAGAIN || errno == EINTR))
+			continue;
+		return ret >= 0? ret : -E_WRITE;
+	}
+}
+
+
+/**
+ * Write the whole buffer to a file descriptor.
+ *
+ * \param fd The file descriptor to write to.
+ * \param buf The buffer to write.
+ * \param size The length of \a buf in bytes.
+ *
+ * This function writes the given buffer and continues on short writes and
+ * when interrupted by a signal.
+ *
+ * \return Positive on success, negative on errors. Possible errors: any
+ * errors returned by para_write().
+ *
+ * \sa para_write().
+ */
+ssize_t write_all(int fd, const void *buf, size_t size)
+{
+//	DEBUG_LOG("writing %zu bytes\n", size);
+	const char *b = buf;
+	while (size) {
+		ssize_t ret = para_write(fd, b, size);
+//		DEBUG_LOG("ret: %zd\n", ret);
+		if (ret < 0)
+			return ret;
+		b += ret;
+		size -= ret;
 	}
 	return 1;
 }
 
+/**
+ * Wrapper for the open(2) system call.
+ *
+ * \param path The filename.
+ * \param flags The usual open(2) flags.
+ * \param mode Specifies the permissions to use.
+ *
+ * The mode parameter must be specified when O_CREAT is in the flags, and is
+ * ignored otherwise.
+ *
+ * \return The file descriptor on success, negative on errors.
+ *
+ * \sa open(2).
+ */
+int para_open(const char *path, int flags, mode_t mode)
+{
+	int ret = open(path, flags, mode);
+
+	if (ret >= 0)
+		return ret;
+	return -ERRNO_TO_ERROR(errno);
+}
+
+/**
+ * Open a file, write the given buffer and close the file.
+ *
+ * \param filename Full path to the file to open.
+ * \param buf The buffer to write to the file.
+ * \param size The size of \a buf.
+ *
+ * \return Positive on success, negative on errors. Possible errors include:
+ * any errors from para_open() or para_write().
+ *
+ * \sa para_open(), para_write().
+ */
+int para_write_file(const char *filename, const void *buf, size_t size)
+{
+	int ret, fd;
+
+	ret = para_open(filename, O_WRONLY | O_CREAT | O_EXCL, 0644);
+	if (ret < 0)
+		return ret;
+	fd = ret;
+	ret = write_all(fd, buf, size);
+	if (ret < 0)
+		goto out;
+	ret = 1;
+out:
+	close(fd);
+	return ret;
+}
+
+
 /**
  * Check whether a file exists.
  *
@@ -205,29 +291,6 @@ void *para_mmap(size_t length, int prot, int flags, int fd, off_t offset)
 	exit(EXIT_FAILURE);
 }
 
-/**
- * Wrapper for the open(2) system call.
- *
- * \param path The filename.
- * \param flags The usual open(2) flags.
- * \param mode Specifies the permissions to use.
- *
- * The mode parameter must be specified when O_CREAT is in the flags, and is
- * ignored otherwise.
- *
- * \return The file descriptor on success, negative on errors.
- *
- * \sa open(2).
- */
-int para_open(const char *path, int flags, mode_t mode)
-{
-	int ret = open(path, flags, mode);
-
-	if (ret >= 0)
-		return ret;
-	return -ERRNO_TO_ERROR(errno);
-}
-
 /**
  * Wrapper for chdir(2).
  *
diff --git a/fd.h b/fd.h
index 22141be..da0d349 100644
--- a/fd.h
+++ b/fd.h
@@ -24,3 +24,4 @@ int mmap_full_file(const char *filename, int open_mode, void **map,
 	size_t *size, int *fd_ptr);
 int para_munmap(void *start, size_t length);
 int write_ok(int fd);
+int para_write_file(const char *filename, const void *buf, size_t size);
-- 
2.39.5