grep doc: add --break / --heading / -W to synopsis

[git.git] / pager.c

diff --git a/pager.c b/pager.c
index 2c7e8ecb3c0860b00113e348008415ca28a7ff72..b7909678f459d90d1c8907c78bb5fcb512fe558d 100644 (file)
--- a/pager.c
+++ b/pager.c
@@ -11,8 +11,6 @@
  * something different on Windows.
  */
 
-static int spawned_pager;
-
 #ifndef WIN32
 static void pager_preexec(void)
 {
@@ -48,11 +46,11 @@ static void wait_for_pager_signal(int signo)
        raise(signo);
 }
 
-const char *git_pager(void)
+const char *git_pager(int stdout_is_tty)
 {
        const char *pager;
 
-       if (!isatty(1))
+       if (!stdout_is_tty)
                return NULL;
 
        pager = getenv("GIT_PAGER");
@@ -73,12 +71,18 @@ const char *git_pager(void)
 
 void setup_pager(void)
 {
-       const char *pager = git_pager();
+       const char *pager = git_pager(isatty(1));
 
        if (!pager)
                return;
 
-       spawned_pager = 1; /* means we are emitting to terminal */
+       /*
+        * force computing the width of the terminal before we redirect
+        * the standard output to the pager.
+        */
+       (void) term_columns();
+
+       setenv("GIT_PAGER_IN_USE", "true", 1);
 
        /* spawn the pager */
        pager_argv[0] = pager;
@@ -109,10 +113,37 @@ void setup_pager(void)
 int pager_in_use(void)
 {
        const char *env;
-
-       if (spawned_pager)
-               return 1;
-
        env = getenv("GIT_PAGER_IN_USE");
        return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
 }
+
+/*
+ * Return cached value (if set) or $COLUMNS environment variable (if
+ * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
+ * and default to 80 if all else fails.
+ */
+int term_columns(void)
+{
+       static int term_columns_at_startup;
+
+       char *col_string;
+       int n_cols;
+
+       if (term_columns_at_startup)
+               return term_columns_at_startup;
+
+       term_columns_at_startup = 80;
+
+       col_string = getenv("COLUMNS");
+       if (col_string && (n_cols = atoi(col_string)) > 0)
+               term_columns_at_startup = n_cols;
+#ifdef TIOCGWINSZ
+       else {
+               struct winsize ws;
+               if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
+                       term_columns_at_startup = ws.ws_col;
+       }
+#endif
+
+       return term_columns_at_startup;
+}