From b0326fb63170801353cbc4d53b80846381de82f4 Mon Sep 17 00:00:00 2001
From: Jan Breuer <jan.breuer@jaybee.cz>
Date: 周五, 08 11月 2013 02:14:38 +0800
Subject: [PATCH] Implement compose compound command functionality
---
libscpi/src/utils.c | 82 +++++++++++++++++++++++++++++++++++++++--
1 files changed, 78 insertions(+), 4 deletions(-)
diff --git a/libscpi/src/utils.c b/libscpi/src/utils.c
index 5498cf2..6a41e54 100644
--- a/libscpi/src/utils.c
+++ b/libscpi/src/utils.c
@@ -54,7 +54,7 @@
* @param set
* @return
*/
-char * strnpbrk(const char *str, size_t size, const char *set) {
+const char * strnpbrk(const char *str, size_t size, const char *set) {
const char *scanp;
long c, sc;
const char * strend = str + size;
@@ -62,7 +62,7 @@
while ((strend != str) && ((c = *str++) != 0)) {
for (scanp = set; (sc = *scanp++) != '\0';)
if (sc == c)
- return ((char *) (str - 1));
+ return str - 1;
}
return (NULL);
}
@@ -401,7 +401,7 @@
*/
size_t patternSeparatorPos(const char * pattern, size_t len) {
- char * separator = strnpbrk(pattern, len, "?:[]");
+ const char * separator = strnpbrk(pattern, len, "?:[]");
if (separator == NULL) {
return len;
} else {
@@ -416,7 +416,7 @@
* @return position of separator or len
*/
size_t cmdSeparatorPos(const char * cmd, size_t len) {
- char * separator = strnpbrk(cmd, len, ":?");
+ const char * separator = strnpbrk(cmd, len, ":?");
size_t result;
if (separator == NULL) {
result = len;
@@ -573,6 +573,80 @@
return result;
}
+/**
+ * Compose command from previsou command anc current command
+ *
+ * @param ptr_prev pointer to previous command
+ * @param len_prev length of previous command
+ * @param pptr pointer to pointer of current command
+ * @param plen pointer to length of current command
+ *
+ * ptr_prev and ptr should be in the same memory buffer
+ *
+ * Function will add part of previous command prior to ptr_prev
+ *
+ * char * cmd = "meas:volt:dc?;ac?"
+ * char * ptr_prev = cmd;
+ * size_t len_prev = 13;
+ * char * ptr = cmd + 14;
+ * size_t len = 3;
+ *
+ * composeCompoundCommand(ptr_prev, len_prev, &ptr, &len);
+ *
+ * after calling this
+ *
+ *
+ *
+ */
+bool_t composeCompoundCommand(char * ptr_prev, size_t len_prev,
+ char ** pptr, size_t * plen) {
+ char * ptr;
+ size_t len;
+ size_t i;
+
+ /* Invalid input */
+ if (pptr == NULL || plen == NULL)
+ return FALSE;
+
+ /* no previous command - nothing to do*/
+ if (ptr_prev == NULL || len_prev == 0)
+ return TRUE;
+
+ ptr = *pptr;
+ len = *plen;
+
+ /* No current command */
+ if (len == 0 || ptr == NULL)
+ return FALSE;
+
+ /* Common command or command root - nothing to do */
+ if (ptr[0] == '*' || ptr[0] == ':')
+ return TRUE;
+
+ /* Previsou command was common command - nothing to do */
+ if (ptr_prev[0] == '*')
+ return TRUE;
+
+ /* Find last occurence of ':' */
+ for (i = len_prev; i > 0; i--) {
+ if (ptr_prev[i-1] == ':') {
+ break;
+ }
+ }
+
+ /* Previous command was simple command - nothing to do*/
+ if (i == 0)
+ return TRUE;
+
+ ptr -= i;
+ len += i;
+ memmove(ptr, ptr_prev, i);
+ *plen = len;
+ *pptr = ptr;
+ return TRUE;
+}
+
+
#if !HAVE_STRNLEN
/* use FreeBSD strnlen */
--
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