X-Git-Url: http://git.tuebingen.mpg.de/?p=osl.git;a=blobdiff_plain;f=fd.c;h=7d69a2f35b6fb3fe08ce487b6c02d3ebe557c9f2;hp=95976d6817fba4e6571f4a2ac3eab3673af18353;hb=dfd3368c03d72660b1e5dba55b23395e234d0963;hpb=093138ba762b3179f4d0375bbaf4250b9e016289

diff --git a/fd.c b/fd.c
index 95976d6..7d69a2f 100644
--- a/fd.c
+++ b/fd.c
@@ -15,6 +15,34 @@
 #include "log.h"
 #include "osl.h"
 #include "error.h"
+#include "fd.h"
+
+/**
+ * Wrapper for the write system call.
+ *
+ * \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, a
+ * negative error code is returned.
+ *
+ * \sa write(2).
+ */
+static ssize_t __write(int fd, const void *buf, size_t size)
+{
+	ssize_t ret;
+
+	for (;;) {
+		ret = write(fd, buf, size);
+		if ((ret < 0) && (errno == EAGAIN || errno == EINTR))
+			continue;
+		return ret >= 0? ret : -ERRNO_TO_ERROR(errno);
+	}
+}
 
 /**
  * Write a buffer to a file descriptor, re-write on short writes.
@@ -33,9 +61,9 @@ int write_all(int fd, const char *buf, size_t *len)
 	assert(total);
 	*len = 0;
 	while (*len < total) {
-		int ret = write(fd, buf + *len, total - *len);
-		if (ret == -1)
-			return -ERRNO_TO_ERROR(errno);
+		int ret = __write(fd, buf + *len, total - *len);
+		if (ret < 0)
+			return ret;
 		*len += ret;
 	}
 	return 1;
@@ -64,6 +92,32 @@ int osl_open(const char *path, int flags, mode_t mode)
 	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 Standard.
+ */
+int write_file(const char *filename, const void *buf, size_t size)
+{
+	int ret, fd;
+
+	ret = osl_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;
+}
+
 /**
  * Wrapper for chdir(2).
  *
@@ -212,7 +266,7 @@ out:
  *
  * \sa munmap(2), mmap_full_file().
  */
-int para_munmap(void *start, size_t length)
+int osl_munmap(void *start, size_t length)
 {
 	int err;
 	if (munmap(start, length) >= 0)
@@ -222,3 +276,77 @@ int para_munmap(void *start, size_t length)
 		strerror(err));
 	return -ERRNO_TO_ERROR(err);
 }
+
+/**
+ * Allocate a sufficiently large string and print into it.
+ *
+ * \param fmt A usual format string.
+ *
+ * Produce output according to \p fmt. No artificial bound on the length of the
+ * resulting string is imposed.
+ *
+ * \return This function either returns a pointer to a string that must be
+ * freed by the caller or \p NULL if memory allocation failed.
+ *
+ * \sa printf(3).
+ */
+__must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
+{
+	int n;
+	size_t size = 100;
+	char *p = malloc(size);
+
+	if (!p)
+		return NULL;
+	while (1) {
+		char *q;
+		va_list ap;
+		/* Try to print in the allocated space. */
+		va_start(ap, fmt);
+		n = vsnprintf(p, size, fmt, ap);
+		va_end(ap);
+		/* If that worked, return the string. */
+		if (n > -1 && n < size)
+			break;
+		/* Else try again with more space. */
+		if (n > -1) /* glibc 2.1 */
+			size = n + 1; /* precisely what is needed */
+		else /* glibc 2.0 */
+			size *= 2; /* twice the old size */
+		q = realloc(p, size);
+		if (!q) {
+			free(p);
+			return NULL;
+		}
+		p = q;
+	}
+	return p;
+}
+
+/**
+ * A wrapper for truncate(2)
+ *
+ * \param path Name of the regular file to truncate
+ * \param size Number of bytes to \b shave \b off
+ *
+ * Truncate the regular file named by \a path by \a size bytes.
+ *
+ * \return Standard.
+ *
+ * \sa truncate(2)
+ */
+int truncate_file(const char *path, off_t size)
+{
+	int ret;
+	struct stat statbuf;
+
+	ret = osl_stat(path, &statbuf);
+	if (ret < 0)
+		return ret;
+	ret = -E_OSL_BAD_SIZE;
+	if (statbuf.st_size < size)
+		return ret;
+	if (truncate(path, statbuf.st_size - size) < 0)
+		return -ERRNO_TO_ERROR(errno);
+	return 1;
+}