introduce help search

introduce search string to narrow down help output
j123b567 · MisterHW · Feb 1, 2022 · Feb 2, 2022 · Feb 3, 2022 · Feb 7, 2022
commit 315f20dfb62992f22dcc55a661dbac7152dcaae7
diff --git a/libscpi/inc/scpi/config.h b/libscpi/inc/scpi/config.h
@@ -118,6 +118,10 @@ extern "C" {
 #define USE_DEPRECATED_FUNCTIONS 1
 #endif
 
+#ifndef USE_HELP_SEARCH
+#define USE_HELP_SEARCH 1
+#endif
+
 #ifndef USE_CUSTOM_DTOSTRE
 #define USE_CUSTOM_DTOSTRE 0
 #endif

diff --git a/libscpi/src/minimal.c b/libscpi/src/minimal.c
@@ -215,20 +215,30 @@ scpi_result_t SCPI_StatusPreset(scpi_t * context) {
 }
 
 /**
- * HELP?
+ * HELP? [<string>]
  * @param context
  * @return
  */
 scpi_result_t SCPI_HelpQ(scpi_t * context) {
-    int i = 0;
-    for(;;) {
+#if USE_HELP_SEARCH
+    size_t search_string_len = 0;
+    const char * search_string = NULL;
+    scpi_bool_t narrowed_down = SCPI_ParamCharacters(context, &search_string, &search_string_len, false);
+#endif
+
+    for(int i = 0; context->cmdlist[i].pattern != NULL; i++) {
         size_t pattern_len = strlen(context->cmdlist[i].pattern);
+#if USE_HELP_SEARCH
+        if(narrowed_down && not strncasestrn(context->cmdlist[i].pattern, pattern_len, search_string, search_string_len)){
+	        continue;
+        }
+#endif
         size_t block_len = 1 + pattern_len + strlen(SCPI_LINE_ENDING);
 #if USE_COMMAND_DESCRIPTIONS
         size_t description_len = context->cmdlist[i].description ? strlen(context->cmdlist[i].description) : 0;
         if(description_len > 0){
             block_len = 1 + pattern_len + 1 + description_len + strlen(SCPI_LINE_ENDING);
-            }
+        }
 #endif
         SCPI_ResultArbitraryBlockHeader(context, block_len);
         SCPI_ResultArbitraryBlockData(context, "\t", 1);
@@ -240,9 +250,6 @@ scpi_result_t SCPI_HelpQ(scpi_t * context) {
         }
 #endif
         SCPI_ResultArbitraryBlockData(context, SCPI_LINE_ENDING, strlen(SCPI_LINE_ENDING));
-        if (context->cmdlist[++i].pattern == NULL) {
-            break;
-        }
     }
     return SCPI_RES_OK;
 }
diff --git a/libscpi/src/utils.c b/libscpi/src/utils.c
@@ -1140,3 +1140,63 @@ uint64_t SCPI_Swap64(uint64_t val) {
             ((val & 0x00FF000000000000ull) >> 40) |
             ((val & 0xFF00000000000000ull) >> 56);
 }
+
+
+/* Cherokee: strncasestrn() and strncasestr()
+ *
+ * Authors:
+ *      Alvaro Lopez Ortega <alvaro@alobbs.com>
+ *
+ * Copyright (C) 2001-2014 Alvaro Lopez Ortega
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#define CHEROKEE_CHAR_TO_LOWER(_ch)     ((_ch) | 32)
+#define CHEROKEE_CHAR_TO_UPPER(_ch)     ((_ch) & ~32)
+
+char * strncasestrn (const char *s, size_t slen, const char *find, size_t findlen)
+{
+    char c;
+    char sc;
+
+    if (unlikely (find == NULL) || (findlen == 0))
+        return (char *)s;
+
+    if (unlikely (*find == '\0'))
+        return (char *)s;
+
+    c = *find;
+    find++;
+    findlen--;
+
+    do {
+        do {
+            if (slen-- < 1 || (sc = *s++) == '\0')
+                return NULL;
+        } while (CHEROKEE_CHAR_TO_LOWER(sc) != CHEROKEE_CHAR_TO_LOWER(c));
+        if (findlen > slen) {
+            return NULL;
+        }
+    } while (strncasecmp (s, find, findlen) != 0);
+
+    s--;
+    return (char *)s;
+}
+
+char * strncasestr (const char *s, const char *find, size_t slen)
+{
+    return strncasestrn (s, slen, find, strlen(find));
+}
diff --git a/libscpi/src/utils_private.h b/libscpi/src/utils_private.h
@@ -99,6 +99,13 @@ extern "C" {
     char *OUR_strndup(const char *s, size_t n);
 #endif
 
+    char * strncasestr  (const char *s, const char *find, size_t slen);
+    char * strncasestrn (const char *s, size_t slen, const char *find, size_t findlen);
+
+#ifndef strncasestrn_s
+#define strncasestrn_s(s,s_len,lit) strncasestrn(s, s_len, lit, sizeof(lit)-1)
+#endif
+
 #ifndef min
 #define min(a, b)  (((a) < (b)) ? (a) : (b))
 #endif