Add the history command

Signed-off-by: Steve Bennett <steveb@workware.net.au>

3 files changed, 155 insertions, 0 deletions

diff --git a/auto.def b/auto.def
index 6c241d7..7eb00ca 100644
--- a/auto.def
+++ b/auto.def
@@ -26,6 +26,7 @@ options {
         exec      - Tcl-compatible exec command
         file      - Tcl-compatible file command
         glob      - Tcl-compatible glob command
+        history   - Tcl access to interactive history
         readdir   - Required for glob
         package   - Package management with the package command
         load      - Load binary extensions at runtime with load or package
@@ -195,6 +196,7 @@ dict set extdb attrs {
     exec      { static }
     file      {}
     glob      { tcl }
+    history   {}
     load      { static }
     mk        { cpp optional }
     oo        { tcl optional full }
diff --git a/examples/jtclsh.tcl b/examples/jtclsh.tcl
new file mode 100644
index 0000000..dc92bca
--- /dev/null
+++ b/examples/jtclsh.tcl
@@ -0,0 +1,36 @@
+# Simple example of how the history extension
+# can be used to provide line editing and history
+
+# Build jimsh with the history extension and enable line editing (the default)
+# ./configure --with-ext=history
+
+package require history
+
+set histfile [env HOME]/.jtclsh
+history load $histfile
+while 1 {
+	if {[history getline "jim> " cmd] < 0} {
+		break
+	}
+	if {$cmd eq "h"} {
+		history show
+		continue
+	}
+	# Don't bother adding single char commands to the history
+	if {[string length $cmd] > 1} {
+		history add $cmd
+		history save $histfile
+	}
+	# jimsh also does:
+	# - check for a complete command: [info complete]
+	# - handle other non-error return codes and changes the prompt: [info returncodes]
+	# - displays the complete error message: [errorInfo]
+	try {
+		set result [eval $cmd]
+		if {$result ne {}} {
+			puts $result
+		}
+	} on error msg {
+		puts $msg
+	}
+}
diff --git a/jim-history.c b/jim-history.c
new file mode 100644
index 0000000..d46ed7f
--- /dev/null
+++ b/jim-history.c
@@ -0,0 +1,117 @@
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "jim.h"
+#include "jimautoconf.h"
+#include "jim-subcmd.h"
+
+static int history_cmd_getline(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+    Jim_Obj *objPtr;
+    char *line = Jim_HistoryGetline(Jim_String(argv[0]));
+
+    /* On EOF returns -1 if varName was specified, or the empty string. */
+    if (line == NULL) {
+        if (argc == 2) {
+            Jim_SetResultInt(interp, -1);
+        }
+        return JIM_OK;
+    }
+
+    objPtr = Jim_NewStringObjNoAlloc(interp, line, -1);
+
+    /* Returns the length of the string if varName was specified */
+    if (argc == 2) {
+        if (Jim_SetVariable(interp, argv[1], objPtr) != JIM_OK) {
+            Jim_FreeNewObj(interp, objPtr);
+            return JIM_ERR;
+        }
+        Jim_SetResultInt(interp, Jim_Length(objPtr));
+    }
+    else {
+        Jim_SetResult(interp, objPtr);
+    }
+    return JIM_OK;
+}
+
+static int history_cmd_load(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+    Jim_HistoryLoad(Jim_String(argv[0]));
+    return JIM_OK;
+}
+
+static int history_cmd_save(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+    Jim_HistorySave(Jim_String(argv[0]));
+    return JIM_OK;
+}
+
+static int history_cmd_add(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+    Jim_HistoryAdd(Jim_String(argv[0]));
+    return JIM_OK;
+}
+
+static int history_cmd_show(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+    Jim_HistoryShow();
+    return JIM_OK;
+}
+
+static const jim_subcmd_type history_command_table[] = {
+    {   "getline",
+        "prompt ?varname?",
+        history_cmd_getline,
+        1,
+        2,
+        /* Description: Reads one line from the user. Similar to gets. */
+    },
+    {   "load",
+        "filename",
+        history_cmd_load,
+        1,
+        1,
+        /* Description: Loads history from the given file, if possible */
+    },
+    {   "save",
+        "filename",
+        history_cmd_save,
+        1,
+        1,
+        /* Description: Saves history to the given file */
+    },
+    {   "add",
+        "line",
+        history_cmd_add,
+        1,
+        1,
+        /* Description: Adds the line to the history ands saves */
+    },
+    {   "show",
+        NULL,
+        history_cmd_show,
+        0,
+        0,
+        /* Description: Displays the history */
+    },
+    { NULL }
+};
+
+static int JimHistorySubCmdProc(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+    return Jim_CallSubCmd(interp, Jim_ParseSubCmd(interp, history_command_table, argc, argv), argc, argv);
+}
+
+int Jim_historyInit(Jim_Interp *interp)
+{
+    void **history;
+    if (Jim_PackageProvide(interp, "history", "1.0", JIM_ERRMSG))
+        return JIM_ERR;
+
+    history = Jim_Alloc(sizeof(*history));
+    *history = NULL;
+
+    Jim_CreateCommand(interp, "history", JimHistorySubCmdProc, history, NULL);
+    return JIM_OK;
+}