Take commands from the environment

diff --git a/tig.c b/tig.c
index 6788d0e8d01142d7effdc1f8493e6ce2a5837e37..910c6fcb46c4cb762a378f26ce05df5de3bd0fb2 100644 (file)
--- a/tig.c
+++ b/tig.c
@@ -46,7 +46,7 @@
 
 static void die(const char *err, ...);
 static void report(const char *msg, ...);
-static void set_nonblocking_input(int boolean);
+static void set_nonblocking_input(bool loading);
 
 #define ABS(x)         ((x) >= 0  ? (x) : -(x))
 #define MIN(x, y)      ((x) < (y) ? (x) :  (y))
@@ -195,7 +195,7 @@ parse_options(int argc, char *argv[])
 
                /**
                 * -l::
-                *      Start up in log view.
+                *      Start up in log view using the internal log command.
                 **/
                if (!strcmp(opt, "-l")) {
                        opt_request = REQ_VIEW_LOG;
@@ -204,7 +204,7 @@ parse_options(int argc, char *argv[])
 
                /**
                 * -d::
-                *      Start up in diff view.
+                *      Start up in diff view using the internal diff command.
                 **/
                if (!strcmp(opt, "-d")) {
                        opt_request = REQ_VIEW_DIFF;
@@ -584,13 +584,59 @@ init_colors(void)
 }
 
 
+/**
+ * ENVIRONMENT VARIABLES
+ * ---------------------
+ * It is possible to alter which commands are used for the different views.
+ * If for example you prefer commits in the main to be sorted by date and
+ * only show 500 commits, use:
+ *
+ *     $ TIG_MAIN_CMD="git log --date-order -n500 --pretty=raw %s" tig
+ *
+ * Or set the variable permanently in your environment.
+ *
+ * Notice, how `%s` is used to specify the commit reference. There can
+ * be a maximum of 5 `%s` ref specifications.
+ *
+ * TIG_DIFF_CMD::
+ *     The command used for the diff view. By default, git show is used
+ *     as a backend.
+ *
+ * TIG_LOG_CMD::
+ *     The command used for the log view.
+ *
+ * TIG_MAIN_CMD::
+ *     The command used for the main view. Note, you must always specify
+ *     the option: `--pretty=raw` since the main view parser expects to
+ *     read that format.
+ **/
+
+#define TIG_DIFF_CMD \
+       "git show --patch-with-stat --find-copies-harder -B -C %s"
+
+#define TIG_LOG_CMD    \
+       "git log --cc --stat -n100 %s"
+
+#define TIG_MAIN_CMD \
+       "git log --topo-order --stat --pretty=raw %s"
+
+/* We silently ignore that the following are also exported. */
+
+#define TIG_HELP_CMD \
+       "man tig 2> /dev/null"
+
+#define TIG_PAGER_CMD \
+       ""
+
+
 /*
  * Viewer
  */
 
 struct view {
        const char *name;       /* View name */
-       const char *cmdfmt;     /* Default command line format */
+       char *cmd_fmt;          /* Default command line format */
+       char *cmd_env;          /* Command line set via environment */
        char *id;               /* Points to either of ref_{head,commit} */
        size_t objsize;         /* Size of objects in the line index */
 
@@ -628,27 +674,21 @@ struct view {
 static struct view_ops pager_ops;
 static struct view_ops main_ops;
 
-#define DIFF_CMD \
-       "git show --patch-with-stat --find-copies-harder -B -C %s"
-
-#define LOG_CMD        \
-       "git log --cc --stat -n100 %s"
-
-#define MAIN_CMD \
-       "git log --topo-order --stat --pretty=raw %s"
-
-#define HELP_CMD \
-       "man tig 2> /dev/null"
-
 char ref_head[SIZEOF_REF]      = "HEAD";
 char ref_commit[SIZEOF_REF]    = "HEAD";
 
+#define VIEW_STR(name, cmd, env, ref, objsize, ops) \
+       { name, cmd, #env, ref, objsize, ops }
+
+#define VIEW_(id, name, ops, ref, objsize) \
+       VIEW_STR(name, TIG_##id##_CMD,  TIG_##id##_CMD, ref, objsize, ops)
+
 static struct view views[] = {
-       { "main",  MAIN_CMD,  ref_head,   sizeof(struct commit), &main_ops },
-       { "diff",  DIFF_CMD,  ref_commit, sizeof(char),          &pager_ops },
-       { "log",   LOG_CMD,   ref_head,   sizeof(char),          &pager_ops },
-       { "help",  HELP_CMD,  ref_head,   sizeof(char),          &pager_ops },
-       { "pager", "",        "static",   sizeof(char),          &pager_ops },
+       VIEW_(MAIN,  "main",  &main_ops,  ref_head,   sizeof(struct commit)),
+       VIEW_(DIFF,  "diff",  &pager_ops, ref_commit, sizeof(char)),
+       VIEW_(LOG,   "log",   &pager_ops, ref_head,   sizeof(char)),
+       VIEW_(HELP,  "help",  &pager_ops, ref_head,   sizeof(char)),
+       VIEW_(PAGER, "pager", &pager_ops, "static",   sizeof(char)),
 };
 
 #define VIEW(req) (&views[(req) - REQ_OFFSET - 1])
@@ -955,8 +995,10 @@ begin_update(struct view *view)
                 * invalid so clear it. */
                view->ref[0] = 0;
        } else {
-               if (snprintf(view->cmd, sizeof(view->cmd), view->cmdfmt,
-                            id, id, id) >= sizeof(view->cmd))
+               char *format = view->cmd_env ? view->cmd_env : view->cmd_fmt;
+
+               if (snprintf(view->cmd, sizeof(view->cmd), format,
+                            id, id, id, id, id) >= sizeof(view->cmd))
                        return FALSE;
        }
 
@@ -1596,19 +1638,14 @@ report(const char *msg, ...)
 
 /* Controls when nodelay should be in effect when polling user input. */
 static void
-set_nonblocking_input(int loading)
+set_nonblocking_input(bool loading)
 {
        /* The number of loading views. */
        static unsigned int nloading;
 
-       if (loading == TRUE) {
-               if (nloading++ == 0)
-                       nodelay(status_win, TRUE);
-               return;
-       }
-
-       if (nloading-- == 1)
-               nodelay(status_win, FALSE);
+       if ((loading == FALSE && nloading-- == 1) ||
+           (loading == TRUE  && nloading++ == 0))
+               nodelay(status_win, loading);
 }
 
 static void
@@ -1678,19 +1715,23 @@ static void die(const char *err, ...)
 int
 main(int argc, char *argv[])
 {
+       struct view *view;
        enum request request;
+       size_t i;
 
        signal(SIGINT, quit);
 
        if (!parse_options(argc, argv))
                return 0;
 
+       for (i = 0; i < ARRAY_SIZE(views) && (view = &views[i]); i++)
+               view->cmd_env = getenv(view->cmd_env);
+
        request = opt_request;
 
        init_display();
 
        while (view_driver(display[current_view], request)) {
-               struct view *view;
                int key;
                int i;