lib: Add function to extract a number from the end of a string

Split out the code in fdtdec which finds a number at the end of a string. It
can be useful in other situations.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/include/vsprintf.h b/include/vsprintf.h
index d2fcca3f5a78e7f63ec4cfabaeb2c4cc3654092a..b5bc9c1d95fab6c09d6cf637202b10ae57e9f85f 100644 (file)
--- a/include/vsprintf.h
+++ b/include/vsprintf.h
@@ -40,6 +40,32 @@ unsigned long long simple_strtoull(const char *cp, char **endp,
                                        unsigned int base);
 long simple_strtol(const char *cp, char **endp, unsigned int base);
 
+/**
+ * trailing_strtol() - extract a trailing integer from a string
+ *
+ * Given a string this finds a trailing number on the string and returns it.
+ * For example, "abc123" would return 123.
+ *
+ * @str:       String to exxamine
+ * @return training number if found, else -1
+ */
+long trailing_strtol(const char *str);
+
+/**
+ * trailing_strtoln() - extract a trailing integer from a fixed-length string
+ *
+ * Given a fixed-length string this finds a trailing number on the string
+ * and returns it. For example, "abc123" would return 123. Only the
+ * characters between @str and @end - 1 are examined. If @end is NULL, it is
+ * set to str + strlen(str).
+ *
+ * @str:       String to exxamine
+ * @end:       Pointer to end of string to examine, or NULL to use the
+ *             whole string
+ * @return training number if found, else -1
+ */
+long trailing_strtoln(const char *str, const char *end);
+
 /**
  * panic() - Print a message and reset/hang
  *

diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 9c6b3619da24cd9ad5c4894d848298ff380d3419..f6c2b195a356cfa027afb134056e87db3d0b0c80 100644 (file)
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -505,8 +505,7 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int offset,
                const char *prop;
                const char *name;
                const char *slash;
-               const char *p;
-               int len;
+               int len, val;
 
                prop = fdt_getprop_by_offset(blob, prop_offset, &name, &len);
                debug("   - %s, %s\n", name, prop);
@@ -517,12 +516,11 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int offset,
                slash = strrchr(prop, '/');
                if (strcmp(slash + 1, find_name))
                        continue;
-               for (p = name + strlen(name) - 1; p > name; p--) {
-                       if (!isdigit(*p)) {
-                               *seqp = simple_strtoul(p + 1, NULL, 10);
-                               debug("Found seq %d\n", *seqp);
-                               return 0;
-                       }
+               val = trailing_strtol(name);
+               if (val != -1) {
+                       *seqp = val;
+                       debug("Found seq %d\n", *seqp);
+                       return 0;
                }
        }
 

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index a9b8a3ae67fa0817deefa3f1d5d559b97056eeb7..4c82837cc41e8e55899d945e8f27d399a0b0be71 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -166,6 +166,25 @@ unsigned long long simple_strtoull(const char *cp, char **endp,
        return result;
 }
 
+long trailing_strtoln(const char *str, const char *end)
+{
+       const char *p;
+
+       if (!end)
+               end = str + strlen(str);
+       for (p = end - 1; p > str; p--) {
+               if (!isdigit(*p))
+                       return simple_strtoul(p + 1, NULL, 10);
+       }
+
+       return -1;
+}
+
+long trailing_strtol(const char *str)
+{
+       return trailing_strtoln(str, NULL);
+}
+
 /* we use this so that we can do without the ctype library */
 #define is_digit(c)    ((c) >= '0' && (c) <= '9')