strutil: introduce sr_atoul_base() conversion helper (non-decimal)

Introduce a text to number conversion routine which supports non-decimal
bases and optional suffixes, but returns unsigned results and thus covers
a larger range of values. This kind of amends commit 97aa41e9b59c which
introduced the sr_atol_base() routine.

diff --git a/src/libsigrok-internal.h b/src/libsigrok-internal.h
index 19fcccfdc1183674140f0a670783d74c5c7bc1d1..44be53c6515355bc1a92cd608208643acdf06081 100644 (file)
--- a/src/libsigrok-internal.h
+++ b/src/libsigrok-internal.h
@@ -1809,6 +1809,7 @@ SR_PRIV void *sr_resource_load(struct sr_context *ctx, int type,
 
 SR_PRIV int sr_atol(const char *str, long *ret);
 SR_PRIV int sr_atol_base(const char *str, long *ret, char **end, int base);
+SR_PRIV int sr_atoul_base(const char *str, unsigned long *ret, char **end, int base);
 SR_PRIV int sr_atoi(const char *str, int *ret);
 SR_PRIV int sr_atod(const char *str, double *ret);
 SR_PRIV int sr_atof(const char *str, float *ret);

diff --git a/src/strutil.c b/src/strutil.c
index 6ed2b85dcea244059aa4d4d97a40999302f3145d..c22c71757f30e42aa08b9e567eb11eeb9a802850 100644 (file)
--- a/src/strutil.c
+++ b/src/strutil.c
@@ -145,6 +145,60 @@ SR_PRIV int sr_atol_base(const char *str, long *ret, char **end, int base)
        return SR_OK;
 }
 
+/**
+ * Convert a text to a number including support for non-decimal bases.
+ * Also optionally returns the position after the number, where callers
+ * can either error out, or support application specific suffixes.
+ *
+ * @param[in] str The input text to convert.
+ * @param[out] ret The conversion result.
+ * @param[out] end The position after the number.
+ * @param[in] base The number format's base, can be 0.
+ *
+ * @retval SR_OK Conversion successful.
+ * @retval SR_ERR Conversion failed.
+ *
+ * @private
+ *
+ * This routine is more general than @ref sr_atol(), which strictly
+ * expects the input text to contain just a decimal number, and nothing
+ * else in addition. The @ref sr_atoul_base() routine accepts trailing
+ * text after the number, and supports non-decimal numbers (bin, hex),
+ * including automatic detection from prefix text.
+ */
+SR_PRIV int sr_atoul_base(const char *str, unsigned long *ret, char **end, int base)
+{
+       unsigned long num;
+       char *endptr;
+
+       /* Add "0b" prefix support which strtol(3) may be missing. */
+       while (str && isspace(*str))
+               str++;
+       if (!base && strncmp(str, "0b", strlen("0b")) == 0) {
+               str += strlen("0b");
+               base = 2;
+       }
+
+       /* Run the number conversion. Quick bail out if that fails. */
+       errno = 0;
+       endptr = NULL;
+       num = strtoul(str, &endptr, base);
+       if (!endptr || errno) {
+               if (!errno)
+                       errno = EINVAL;
+               return SR_ERR;
+       }
+       *ret = num;
+
+       /* Advance to optional non-space trailing suffix. */
+       while (endptr && isspace(*endptr))
+               endptr++;
+       if (end)
+               *end = endptr;
+
+       return SR_OK;
+}
+
 /**
  * Convert a string representation of a numeric value (base 10) to an integer. The
  * conversion is strict and will fail if the complete string does not represent