Use less on apitrace dump.

Author: jrfonseca

README.markdown

@@ -29,7 +29,7 @@ directory.  You can specify the written trace filename by setting the
 
 View the trace with
 
-    apitrace dump --color application.trace | less -R
+    apitrace dump --color application.trace
 
 Replay an OpenGL trace with
 

cli/CMakeLists.txt

@@ -4,6 +4,7 @@ add_executable (apitrace
     cli_diff_state.cpp
     cli_diff_images.cpp
     cli_dump.cpp
+    cli_pager.cpp
     cli_repack.cpp
     cli_trace.cpp
 )

cli/cli_dump.cpp

@@ -26,6 +26,7 @@
 #include <string.h>
 
 #include "cli.hpp"
+#include "cli_pager.hpp"
 
 #include "trace_parser.hpp"
 
@@ -99,6 +100,7 @@ command(int argc, char *argv[])
         color = COLOR_OPTION_ALWAYS;
 #else
         color = isatty(1) ? COLOR_OPTION_ALWAYS : COLOR_OPTION_NEVER;
+        pipepager();
 #endif
     }
 

cli/cli_pager.cpp

@@ -0,0 +1,153 @@
+/**************************************************************************
+ *
+ * Copyright 2011 Jose Fonseca
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ **************************************************************************/
+
+
+/*
+ * Pager abstraction.
+ */
+
+
+#include "cli.hpp"
+
+
+#if defined(_WIN32)
+
+
+void
+pipepager(void) {
+    /* no-op */
+}
+
+
+#else /* !defined(_WIN32) */
+
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <fcntl.h>
+
+
+static pid_t pid = -1;
+
+
+/*
+ * Wait for pager process on exit.
+ */
+static void
+on_exit(void)
+{
+	fflush(stdout);
+	fflush(stderr);
+    close(STDOUT_FILENO);
+    close(STDERR_FILENO);
+    waitpid(pid, NULL, 0);
+}
+
+
+/*
+ * Wait for page process on signal.
+ */
+static void
+on_signal(int sig)
+{
+    on_exit();
+    signal(sig, SIG_DFL); 
+    raise(sig);
+}
+
+
+/*
+ * Spawn a pager process and pipe standard output into it.
+ */
+void
+pipepager(void) {
+    if (!isatty(STDOUT_FILENO)) {
+        return;
+    }
+
+    enum {
+        READ_FD  = 0,
+        WRITE_FD = 1
+    };
+
+    int parentToChild[2];
+    int ret;
+    const char *pager;
+
+    ret = pipe(parentToChild);
+    assert(ret == 0);
+
+    pid = fork();
+    switch (pid) {
+    case -1:
+        // failed to fork
+        return;
+
+    case 0:
+        // child
+        ret = dup2(parentToChild[READ_FD], STDIN_FILENO);
+        assert(ret != -1);
+        ret = close(parentToChild[WRITE_FD]);
+        assert(ret == 0);
+
+        pager = getenv("PAGER");
+        if (!pager) {
+            pager = "less";
+        }
+
+        setenv("LESS", "FRXn", 0);
+
+        execlp(pager, pager, NULL);
+
+        // This line should never be reached
+        abort();
+
+    default:
+        // parent
+        ret = close(parentToChild[READ_FD]);
+        assert(ret == 0);
+
+        dup2(parentToChild[WRITE_FD], STDOUT_FILENO);
+        if (isatty(STDERR_FILENO))
+            dup2(parentToChild[WRITE_FD], STDERR_FILENO);
+        close(parentToChild[WRITE_FD]);
+
+        // Ensure we wait for the pager before terminating
+        signal(SIGINT, on_signal);
+        signal(SIGHUP, on_signal);
+        signal(SIGTERM, on_signal);
+        signal(SIGQUIT, on_signal);
+        signal(SIGPIPE, on_signal);
+        atexit(on_exit);
+    }
+}
+
+
+#endif /* !defined(_WIN32) */

cli/cli_pager.hpp

@@ -0,0 +1,35 @@
+/**************************************************************************
+ *
+ * Copyright 2011 Jose Fonseca
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ **************************************************************************/
+
+
+#ifndef _CLI_PAGER_HPP_
+#define _CLI_PAGER_HPP_
+
+
+void
+pipepager(void);
+
+
+#endif /* _CLI_PAGER_HPP_ */