[ovs-dev] [patch_v7 1/6] string: Implement strcasestr if it is missing.

[Darrell Ball]

strcasestr is not defined for Windows, so implement a version
that could be used on Windows. This is needed for an upcoming
patch.

Signed-off-by: Darrell Ball <dlu998 at gmail.com>
---
 lib/string.c    | 41 ++++++++++++++++++++++++++++++++++++++++-
 lib/string.h.in |  1 +
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/lib/string.c b/lib/string.c
index 082359d..445acd7 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -15,9 +15,14 @@
  */
 
 #include <config.h>
-
+#include <ctype.h>
+#include <stdio.h>
 #include <string.h>
 
+#include "util.h"
+
+char *strcasestr_s(const char *str, const char *substr);
+
 #ifndef HAVE_STRNLEN
 size_t
 strnlen(const char *s, size_t maxlen)
@@ -26,3 +31,37 @@ strnlen(const char *s, size_t maxlen)
     return end ? end - s : maxlen;
 }
 #endif
+
+char *strcasestr_s(const char *str, const char *substr)
+{
+    if (!str || !substr) {
+        return NULL;
+    }
+    if (strlen(substr) > strlen(str)) {
+        return NULL;
+    }
+
+    int si = 0;  /* string index. */
+    int wsi = 0; /* working string index. */
+    int ssi = 0; /* substring index. */
+    const char *save_str;
+    while (str[si]) {
+        save_str = &str[si];
+        while (substr[ssi]) {
+            if (toupper(str[wsi]) == toupper(substr[ssi])) {
+                ssi++;
+                wsi++;
+            } else {
+                ssi = 0;
+                si++;
+                wsi = si;
+            }
+            break;
+        }
+        /* We matched the substring. */
+        if (!substr[ssi]) {
+            return CONST_CAST(char *, save_str);
+        }
+    }
+    return NULL;
+}
diff --git a/lib/string.h.in b/lib/string.h.in
index bbdaeb4..5a86ea3 100644
--- a/lib/string.h.in
+++ b/lib/string.h.in
@@ -36,6 +36,7 @@
 #define strcasecmp _stricmp
 #define strncasecmp _strnicmp
 #define strerror_r(errnum, buf, buflen) strerror_s(buf, buflen, errnum)
+#define strcasestr(str, substr) strcasestr_s(str, substr)
 #endif
 
 #ifndef HAVE_STRNLEN
-- 
1.9.1