shell: Rewrite documentation and improve error message

Update the documentation of 'git shell' to mention the interactive
mode and COMMAND_DIR. Also provide a hint when interactive mode is not
available in the shell.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Reviewed-by: Greg Brockman <gdb@MIT.EDU>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-shell.txt b/Documentation/git-shell.txt
index 0f3ad811cfa41e65a3d807a5eb766ce2a66a7831..6403126a029bf43acaa219296353f7ab1f2040a0 100644 (file)
--- a/Documentation/git-shell.txt
+++ b/Documentation/git-shell.txt
@@ -3,24 +3,30 @@ git-shell(1)
 
 NAME
 ----
-git-shell - Restricted login shell for GIT-only SSH access
+git-shell - Restricted login shell for Git-only SSH access
 
 
 SYNOPSIS
 --------
-'$(git --exec-path)/git-shell' -c <command> <argument>
+'git shell' [-c <command> <argument>]
 
 DESCRIPTION
 -----------
-This is meant to be used as a login shell for SSH accounts you want
-to restrict to GIT pull/push access only. It permits execution only
-of server-side GIT commands implementing the pull/push functionality.
-The commands can be executed only by the '-c' option; the shell is not
-interactive.
-
-Currently, only four commands are permitted to be called, 'git-receive-pack'
-'git-upload-pack' and 'git-upload-archive' with a single required argument, or
-'cvs server' (to invoke 'git-cvsserver').
+
+A login shell for SSH accounts to provide restricted Git access. When
+'-c' is given, the program executes <command> non-interactively;
+<command> can be one of 'git receive-pack', 'git upload-pack', 'git
+upload-archive', 'cvs server', or a command in COMMAND_DIR. The shell
+is started in interactive mode when no arguments are given; in this
+case, COMMAND_DIR must exist, and any of the executables in it can be
+invoked.
+
+'cvs server' is a special command which executes git-cvsserver.
+
+COMMAND_DIR is the path "$HOME/git-shell-commands". The user must have
+read and execute permissions to the directory in order to execute the
+programs in it. The programs are executed with a cwd of $HOME, and
+<argument> is parsed as a command-line string.
 
 Author
 ------

diff --git a/shell.c b/shell.c
index e07aef4bf2331765deba3a344a2d1641becb4068..f0f6c2d3be924e976fe1bbc7e962b8ceaf83f37d 100644 (file)
--- a/shell.c
+++ b/shell.c
@@ -149,8 +149,11 @@ int main(int argc, char **argv)
        } else if (argc == 1) {
                /* Allow the user to run an interactive shell */
                cd_to_homedir();
-               if (access(COMMAND_DIR, R_OK | X_OK) == -1)
-                       die("Sorry, the interactive git-shell is not enabled");
+               if (access(COMMAND_DIR, R_OK | X_OK) == -1) {
+                       die("Interactive git shell is not enabled.\n"
+                           "hint: ~/" COMMAND_DIR " should exist "
+                           "and have read and execute access.");
+               }
                run_shell();
                exit(0);
        } else if (argc != 3 || strcmp(argv[1], "-c")) {