Move static `get_hostname()` to `BLI_hostname()` in `system.c`

This makes the `#include <Windows.h>` use more localised and out of the
`image.c` file.

Reviewers: LazyDodo

Reviewed by: LazyDodo

Differential revision: https://developer.blender.org/D4049

2 files changed, 30 insertions, 1 deletions

diff --git a/source/blender/blenlib/BLI_system.h b/source/blender/blenlib/BLI_system.h
index 7f88f8a18b1..3bb47a4a5b7 100644
--- a/source/blender/blenlib/BLI_system.h
+++ b/source/blender/blenlib/BLI_system.h
@@ -34,6 +34,18 @@ void BLI_system_backtrace(FILE *fp);
 /* Get CPU brand, result is to be MEM_freeN()-ed. */
 char *BLI_cpu_brand_string(void);
 
+/**
+ * Obtain the hostname from the system.
+ *
+ * This simply determines the host's name, and doesn't do any DNS lookup of any
+ * IP address of the machine. As such, it's only usable for identification
+ * purposes, and not for reachability over a network.
+ *
+ * @param buffer Character buffer to write the hostname into.
+ * @param bufsize Size of the character buffer, including trailing '\0'.
+ */
+void BLI_hostname_get(char *buffer, size_t bufsize);
+
 /* getpid */
 #ifdef WIN32
 #  define BLI_SYSTEM_PID_H <process.h>
diff --git a/source/blender/blenlib/intern/system.c b/source/blender/blenlib/intern/system.c
index fca168dce69..5ff1d4ed710 100644
--- a/source/blender/blenlib/intern/system.c
+++ b/source/blender/blenlib/intern/system.c
@@ -31,9 +31,10 @@
 
 #include "MEM_guardedalloc.h"
 
-/* for backtrace */
+/* for backtrace and gethostname/GetComputerName */
 #if defined(__linux__) || defined(__APPLE__)
 #  include <execinfo.h>
+#  include <unistd.h>
 #elif defined(WIN32)
 #  include <windows.h>
 #  include <dbghelp.h>
@@ -176,3 +177,19 @@ char *BLI_cpu_brand_string(void)
 	}
 	return NULL;
 }
+
+void BLI_hostname_get(char *buffer, size_t bufsize)
+{
+#ifndef WIN32
+	if (gethostname(buffer, bufsize-1) < 0) {
+		BLI_strncpy(buffer, "-unknown-", bufsize);
+	}
+	/* When gethostname() truncates, it doesn't guarantee the trailing \0. */
+	buffer[bufsize - 1] = '\0';
+#else
+	DWORD bufsize_inout = bufsize;
+	if(!GetComputerName(buffer, &bufsize_inout)) {
+		strncpy(buffer, "-unknown-", bufsize);
+	}
+#endif
+}