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>
This commit is contained in:
Simon Glass 2015-06-23 15:39:08 -06:00
parent 1acab96d97
commit c4af6732c4
3 changed files with 51 additions and 8 deletions

View File

@ -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
*

View File

@ -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;
}
}

View File

@ -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')