From cf7ee481902df64b26ac8b1741eca861a8d2f7cc Mon Sep 17 00:00:00 2001 From: Usman Akinyemi Date: Sat, 15 Feb 2025 21:20:52 +0530 Subject: agent: advertise OS name via agent capability As some issues that can happen with a Git client can be operating system specific, it can be useful for a server to know which OS a client is using. In the same way it can be useful for a client to know which OS a server is using. Our current agent capability is in the form of "package/version" (e.g., "git/1.8.3.1"). Let's extend it to include the operating system name (os) i.e in the form "package/version-os" (e.g., "git/1.8.3.1-Linux"). Including OS details in the agent capability simplifies implementation, maintains backward compatibility, avoids introducing a new capability, encourages adoption across Git-compatible software, and enhances debugging by providing complete environment information without affecting functionality. The operating system name is retrieved using the 'sysname' field of the `uname(2)` system call or its equivalent. However, there are differences between `uname(1)` (command-line utility) and `uname(2)` (system call) outputs on Windows. These discrepancies complicate testing on Windows platforms. For example: - `uname(1)` output: MINGW64_NT-10.0-20348.3.4.10-87d57229.x86_64\ .2024-02-14.20:17.UTC.x86_64 - `uname(2)` output: Windows.10.0.20348 On Windows, uname(2) is not actually system-supplied but is instead already faked up by Git itself. We could have overcome the test issue on Windows by implementing a new `uname` subcommand in `test-tool` using uname(2), but except uname(2), which would be tested against itself, there would be nothing platform specific, so it's just simpler to disable the tests on Windows. Mentored-by: Christian Couder Signed-off-by: Usman Akinyemi Signed-off-by: Junio C Hamano --- Documentation/gitprotocol-v2.txt | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'Documentation/gitprotocol-v2.txt') diff --git a/Documentation/gitprotocol-v2.txt b/Documentation/gitprotocol-v2.txt index 1652fef3ae..9f6350bbf2 100644 --- a/Documentation/gitprotocol-v2.txt +++ b/Documentation/gitprotocol-v2.txt @@ -184,9 +184,13 @@ form `agent=X`) to notify the client that the server is running version the `agent` capability with a value `Y` (in the form `agent=Y`) in its request to the server (but it MUST NOT do so if the server did not advertise the agent capability). The `X` and `Y` strings may contain any -printable ASCII characters except space (i.e., the byte range 32 < x < -127), and are typically of the form "package/version" (e.g., -"git/1.8.3.1"). The agent strings are purely informative for statistics +printable ASCII characters except space (i.e., the byte range 33 <= x <= +126), and are typically of the form "package/version-os" (e.g., +"git/1.8.3.1-Linux") where `os` is the operating system name (e.g., +"Linux"). `X` and `Y` can be configured using the GIT_USER_AGENT +environment variable and it takes priority. The `os` is +retrieved using the 'sysname' field of the `uname(2)` system call +or its equivalent. The agent strings are purely informative for statistics and debugging purposes, and MUST NOT be used to programmatically assume the presence or absence of particular features. -- cgit v1.3