* CLI history: [Preserve CLI command history across sessions. The up/down arrows](https://github.com/clicon/clixon/issues/79)

* The design is similar to bash history:
      * The CLI loads/saves its complete history to a file on entry and exit, respectively
      * The size (number of lines) of the file is the same as the history in memory
      * Only the latest session dumping its history will survive (bash merges multiple session history).
      * Tilde-expansion is supported
      * Files not found or without appropriate access will not cause an exit but will be logged at debug level
  * New config options: CLICON_CLI_HIST_FILE with default value `~/.clixon_cli_history`
  * New config options: CLICON_CLI_HIST_SIZE with default value 300.

CHANGELOG.md

@@ -5,6 +5,15 @@
 ## 3.10.0 (Upcoming)
 
 ### Major New features
+* CLI history: [Preserve CLI command history across sessions. The up/down arrows](https://github.com/clicon/clixon/issues/79)
+  * The design is similar to bash history:
+      * The CLI loads/saves its complete history to a file on entry and exit, respectively
+      * The size (number of lines) of the file is the same as the history in memory
+      * Only the latest session dumping its history will survive (bash merges multiple session history).
+      * Tilde-expansion is supported
+      * Files not found or without appropriate access will not cause an exit but will be logged at debug level
+  * New config options: CLICON_CLI_HIST_FILE with default value `~/.clixon_cli_history`
+  * New config options: CLICON_CLI_HIST_SIZE with default value 300.
 * New backend startup and upgrade support, see [doc/startup.md] for details
   * Enable with CLICON_XMLDB_MODSTATE config option
   * Check modules-state tags when loading a datastore at startup

apps/cli/cli_handle.c

@@ -114,7 +114,7 @@ cli_handle_init(void)
 int
 cli_handle_exit(clicon_handle h)
 {
-    cligen_handle ch = cligen(h);
+    cligen_handle      ch = cligen(h);
     struct cli_handle *cl = handle(h);
 
     if (cl->cl_stx)

apps/cli/cli_main.c

@@ -55,6 +55,7 @@
 #include <pwd.h>
 #include <assert.h>
 #include <libgen.h>
+#include <wordexp.h>
 
 /* cligen */
 #include <cligen/cligen.h>
@@ -72,6 +73,84 @@
 /* Command line options to be passed to getopt(3) */
 #define CLI_OPTS "hD:f:l:F:1a:u:d:m:qp:GLy:c:U:o:"
 
+/*! Check if there is a CLI history file and if so dump the CLI histiry to it
+ * Just log if file does not exist or is not readable
+ * @param[in]  h    CLICON handle
+ */
+static int
+cli_history_load(clicon_handle h)
+{
+    int       retval = -1;
+    int       lines;
+    char     *filename;
+    FILE     *f = NULL;
+    wordexp_t result = {0,}; /* for tilde expansion */
+
+    lines = clicon_option_int(h,"CLICON_CLI_HIST_SIZE");
+    /* Re-init history with clixon lines (1st time was w cligen defaults) */
+    if (cligen_hist_init(cli_cligen(h), lines) < 0)
+	goto done;
+    if ((filename = clicon_option_str(h,"CLICON_CLI_HIST_FILE")) == NULL)
+	goto ok; /* ignore */
+    if (wordexp(filename, &result, 0) < 0){
+	clicon_err(OE_UNIX, errno, "wordexp");
+	goto done;
+    }
+    if ((f = fopen(result.we_wordv[0], "r")) == NULL){
+	clicon_log(LOG_DEBUG, "Warning: Could not open CLI history file for reading: %s: %s",
+		   result.we_wordv[0], strerror(errno));
+	goto ok;
+    }
+    if (cligen_hist_file_load(cli_cligen(h), f) < 0){
+	clicon_err(OE_UNIX, errno, "cligen_hist_file_load");
+	goto done;
+    }
+ ok:
+    retval = 0;
+ done:
+    wordfree(&result);
+    if (f)
+	fclose(f);
+    return retval;
+}
+
+/*! Start CLI history and load from file 
+ * Just log if file does not exist or is not readable
+ * @param[in]  h    CLICON handle
+ */
+static int
+cli_history_save(clicon_handle h)
+{
+    int       retval = -1;
+    char     *filename;
+    FILE     *f = NULL;
+    wordexp_t result = {0,}; /* for tilde expansion */
+
+    if ((filename = clicon_option_str(h, "CLICON_CLI_HIST_FILE")) == NULL)
+	goto ok; /* ignore */
+    if (wordexp(filename, &result, 0) < 0){
+	clicon_err(OE_UNIX, errno, "wordexp");
+	goto done;
+    }
+    if ((f = fopen(result.we_wordv[0], "w+")) == NULL){
+	clicon_log(LOG_DEBUG, "Warning: Could not open CLI history file for writing: %s: %s",
+		   result.we_wordv[0], strerror(errno));
+	goto ok;
+    }
+    if (cligen_hist_file_save(cli_cligen(h), f) < 0){
+	clicon_err(OE_UNIX, errno, "cligen_hist_file_save");
+	goto done;
+    }
+ ok:
+    retval = 0;
+ done:
+    wordfree(&result);
+    if (f)
+	fclose(f);
+    return retval;
+}
+
+
 /*! Clean and close all state of cli process (but dont exit). 
  * Cannot use h after this 
  * @param[in]  h  Clixon handle
@@ -90,6 +169,7 @@ cli_terminate(clicon_handle h)
     if ((x = clicon_conf_xml(h)) != NULL)
 	xml_free(x);
     cli_plugin_finish(h);    
+    cli_history_save(h);
     cli_handle_exit(h);
     clicon_log_exit();
     return 0;
@@ -134,16 +214,18 @@ cli_interactive(clicon_handle h)
 	new_mode = cli_syntax_mode(h);
 	if ((cmd = clicon_cliread(h)) == NULL) {
 	    cligen_exiting_set(cli_cligen(h), 1); /* EOF */
-	    goto done;
+	    goto ok; /* EOF should not be -1 error? */
 	}
 	if ((res = clicon_parse(h, cmd, &new_mode, &eval)) < 0)
 	    goto done;
     }
+ ok:
     retval = 0;
  done:
     return retval;
 }
 
+
 static void
 usage(clicon_handle h,
       char         *argv0)
@@ -182,21 +264,21 @@ usage(clicon_handle h,
 int
 main(int argc, char **argv)
 {
-    int          retval = -1;
+    int            retval = -1;
-    int          c;    
+    int            c;    
-    int          once;
+    int            once;
-    char	*tmp;
+    char	  *tmp;
-    char	*argv0 = argv[0];
+    char	  *argv0 = argv[0];
-    clicon_handle h;
+    clicon_handle  h;
-    int          printgen  = 0;
+    int            printgen  = 0;
-    int          logclisyntax  = 0;
+    int            logclisyntax  = 0;
-    int          help = 0;
+    int            help = 0;
-    int          logdst = CLICON_LOG_STDERR;
+    int            logdst = CLICON_LOG_STDERR;
-    char        *restarg = NULL; /* what remains after options */
+    char          *restarg = NULL; /* what remains after options */
-    yang_spec   *yspec;
+    yang_spec     *yspec;
-    yang_spec   *yspecfg = NULL; /* For config XXX clixon bug */
+    yang_spec     *yspecfg = NULL; /* For config XXX clixon bug */
     struct passwd *pw;
-    char         *str;
+    char          *str;
     
     /* Defaults */
     once = 0;
@@ -459,6 +541,10 @@ main(int argc, char **argv)
     *(argv-1) = tmp;
 
     cligen_line_scrolling_set(cli_cligen(h), clicon_option_int(h,"CLICON_CLI_LINESCROLLING"));
+    /*! Start CLI history and load from file */
+    if (cli_history_load(h) < 0)
+	goto done;
+    /* Experimental utf8 mode */
     cligen_utf8_set(cli_cligen(h), clicon_option_int(h,"CLICON_CLI_UTF8"));
     /* Launch interfactive event loop, unless -1 */
     if (restarg != NULL && strlen(restarg)){
@@ -466,9 +552,8 @@ main(int argc, char **argv)
 	int result;
 
 	/* */
-	if (clicon_parse(h, restarg, &mode, &result) != 1){
+	if (clicon_parse(h, restarg, &mode, &result) != 1)
 	    goto done;
-	}
 	if (result < 0)
 	    goto done;
     }

doc/CLI.md

@@ -1,7 +1,9 @@
 # Clixon CLI
 
 * [CLIgen](#cligen)
-* [Tricks - eg for large specs](#tricks)
+* [Command history](#history)
+* [Large spec designs](#large-specs)
+
 
 ## CLIgen
 
@@ -26,7 +28,18 @@ Clixon adds some features and structure to CLIgen which include:
   The commands (eg `cli_set`) will be called with the first argument an api-path to the referenced object.
 * The CLIgen `treename` syntax does not work.
 
-## Tricks
+## History
+
+Clixon CLI supports persistent command history. There are two CLI history related configuration options: `CLICON_CLI_HIST_FILE` with default value `~/.clixon_cli_history` and `CLICON_CLI_HIST_SIZE` with default value 300.
+
+The design is similar to bash history but is simpler in some respects:
+   * The CLI loads/saves its complete history to a file on entry and exit, respectively
+   * The size (number of lines) of the file is the same as the history in memory
+   * Only the latest session dumping its history will survive (bash merges multiple session history).
+
+Further, tilde-expansion is supported and if history files are not found or lack appropriate access will not cause an exit but will be logged at debug level
+
+## Large specs
 
 CLIgen is designed to handle large specifications in runtime, but it may be
 difficult to handle large specifications from a design perspective.
@@ -79,3 +92,4 @@ You can also add the C preprocessor as a first step. You can then define macros,
    %.cli : %.cpp
         $(CPP) -P -x assembler-with-cpp $(INCLUDES) -o $@ $<
   ```
+

lib/src/clixon_options.c

@@ -183,7 +183,7 @@ parse_configfile(clicon_handle  h,
 	else
 #endif
 	{
-	    clicon_err(OE_CFG, 0, "Config file %s: Lacks top-level \"clixon_config\" element\nClixon config files should begin with: <clixon-config xmlns=\"http://clicon.org/config\" (See Changelog in Clixon 3.10)>", filename);
+	    clicon_err(OE_CFG, 0, "Config file %s: Lacks top-level \"clixon-config\" element\nClixon config files should begin with: <clixon-config xmlns=\"http://clicon.org/config\" (See Changelog in Clixon 3.10)>", filename);
 	    
 	    goto done;
 	}

test/test_cli.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
-# Test1: backend and cli basic functionality
+# Backend and cli basic functionality
 # Start backend server
 # Add an ethernet interface and an address
 # Show configuration

test/test_cli_history.sh

@@ -0,0 +1,109 @@
+#!/bin/bash
+# Basic CLI history test
+
+# Magic line must be first in script (see README.md)
+s="$_" ; . ./lib.sh || if [ "$s" = $0 ]; then exit 0; else return 0; fi
+
+APPNAME=example
+
+# include err() and new() functions and creates $dir
+
+cfg=$dir/conf_yang.xml
+histfile=$dir/histfile
+
+# Use yang in example
+
+cat <<EOF > $cfg
+<clixon-config xmlns="http://clicon.org/config">
+  <CLICON_CONFIGFILE>$cfg</CLICON_CONFIGFILE>
+  <CLICON_YANG_DIR>/usr/local/share/clixon</CLICON_YANG_DIR>
+  <CLICON_YANG_DIR>$IETFRFC</CLICON_YANG_DIR>
+  <CLICON_YANG_MODULE_MAIN>clixon-example</CLICON_YANG_MODULE_MAIN>
+  <CLICON_BACKEND_DIR>/usr/local/lib/$APPNAME/backend</CLICON_BACKEND_DIR>
+  <CLICON_CLISPEC_DIR>/usr/local/lib/$APPNAME/clispec</CLICON_CLISPEC_DIR>
+  <CLICON_CLI_DIR>/usr/local/lib/$APPNAME/cli</CLICON_CLI_DIR>
+  <CLICON_CLI_MODE>$APPNAME</CLICON_CLI_MODE>
+  <CLICON_CLI_HIST_FILE>$histfile</CLICON_CLI_HIST_FILE>
+  <CLICON_CLI_HIST_SIZE>10</CLICON_CLI_HIST_SIZE>
+  <CLICON_SOCK>/usr/local/var/$APPNAME/$APPNAME.sock</CLICON_SOCK>
+  <CLICON_BACKEND_PIDFILE>/usr/local/var/$APPNAME/$APPNAME.pidfile</CLICON_BACKEND_PIDFILE>
+  <CLICON_CLI_GENMODEL_COMPLETION>1</CLICON_CLI_GENMODEL_COMPLETION>
+  <CLICON_XMLDB_DIR>/usr/local/var/$APPNAME</CLICON_XMLDB_DIR>
+  <CLICON_XMLDB_PLUGIN>/usr/local/lib/xmldb/text.so</CLICON_XMLDB_PLUGIN>
+</clixon-config>
+EOF
+
+cat <<EOF > $histfile
+first line
+EOF
+
+# NOTE Backend is not really use here
+new "test params: -f $cfg"
+if [ $BE -ne 0 ]; then
+    new "kill old backend"
+    sudo clixon_backend -z -f $cfg
+    if [ $? -ne 0 ]; then
+	err
+    fi
+    new "start backend -s init -f $cfg"
+    start_backend -s init -f $cfg
+
+    new "waiting"
+    sleep $RCWAIT
+fi
+
+new "cli read and add entry to existing history"
+expecteof "$clixon_cli -f $cfg" 0 "example 42" "data"
+
+new "Check histfile exists"
+if [ ! -f $histfile ]; then
+    err "$histfile" "not found"
+fi
+
+new "Check it has two entries"
+lines=$(cat $histfile | wc -l)
+if [ $lines -ne 2 ]; then
+    err "Line:$lines" "2"
+fi
+
+new "check it contains first line"
+nr=$(grep -c "example 42" $histfile)
+if [ $nr -ne 1 ]; then
+    err "Contains: example 42" "1"
+fi
+
+new "Check it contains example 42"
+nr=$(grep -c "example 42" $histfile)
+if [ $nr -ne 1 ]; then
+    err "Contains: example 42" "1"
+fi
+
+new "cli add entry and create newhist file"
+expecteof "$clixon_cli -f $cfg -o CLICON_CLI_HIST_FILE=$dir/newhist" 0 "example 43" "data"
+
+new "Check newhist exists"
+if [ ! -f $dir/newhist ]; then
+    err "$dir/newhist" "not found"
+fi
+
+new "check it contains example 43"
+nr=$(grep -c "example 43" $dir/newhist)
+if [ $nr -ne 1 ]; then
+    err "Contains: example 43" "1"
+fi
+
+if [ $BE -eq 0 ]; then
+    exit # BE
+fi
+
+new "Kill backend"
+# Check if premature kill
+pid=`pgrep -u root -f clixon_backend`
+if [ -z "$pid" ]; then
+    err "backend already dead"
+fi
+# kill backend
+stop_backend -f $cfg
+
+
+rm -rf $dir

yang/clixon/clixon-config@2019-03-05.yang

@@ -297,6 +297,21 @@ module clixon-config {
                  Note that this feature is EXPERIMENTAL and may not properly handle 
                  scrolling, control characters, etc";
 	}
+	leaf CLICON_CLI_HIST_FILE {
+	    type string;
+	    default "~/.clixon_cli_history";
+	    description
+		"Name of CLI history file. If not given, history is not saved.
+                 The number of lines is saved is given by CLICON_CLI_HIST_SIZE.";
+	}
+	leaf CLICON_CLI_HIST_SIZE {
+	    type int32;
+	    default 300;
+	    description
+		"Number of lines to save in CLI history. 
+                 Also, if CLICON_CLI_HIST_FILE is set, also the size in lines
+                 of the saved history.";
+	}
 	leaf CLICON_SOCK_FAMILY {
 	    type string;
 	    default "UNIX";