On Thu, 30 Jan 2014, Sebastian Capella wrote: > kstrimdup creates a whitespace-trimmed duplicate of the passed > in null-terminated string. This is useful for strings coming > from sysfs that often include trailing whitespace due to user > input. > > Thanks to Joe Perches for this implementation. > > Signed-off-by: Sebastian Capella <sebastian.capella@xxxxxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx> > --- > include/linux/string.h | 1 + > mm/util.c | 30 ++++++++++++++++++++++++++++++ > 2 files changed, 31 insertions(+) > > diff --git a/include/linux/string.h b/include/linux/string.h > index ac889c5..f29f9a0 100644 > --- a/include/linux/string.h > +++ b/include/linux/string.h > @@ -114,6 +114,7 @@ void *memchr_inv(const void *s, int c, size_t n); > > extern char *kstrdup(const char *s, gfp_t gfp); > extern char *kstrndup(const char *s, size_t len, gfp_t gfp); > +extern char *kstrimdup(const char *s, gfp_t gfp); > extern void *kmemdup(const void *src, size_t len, gfp_t gfp); > > extern char **argv_split(gfp_t gfp, const char *str, int *argcp); > diff --git a/mm/util.c b/mm/util.c > index 808f375..a8b731c 100644 > --- a/mm/util.c > +++ b/mm/util.c > @@ -1,6 +1,7 @@ > #include <linux/mm.h> > #include <linux/slab.h> > #include <linux/string.h> > +#include <linux/ctype.h> > #include <linux/export.h> > #include <linux/err.h> > #include <linux/sched.h> > @@ -63,6 +64,35 @@ char *kstrndup(const char *s, size_t max, gfp_t gfp) > EXPORT_SYMBOL(kstrndup); > > /** > + * kstrimdup - Trim and copy a %NUL terminated string. > + * @s: the string to trim and duplicate > + * @gfp: the GFP mask used in the kmalloc() call when allocating memory > + * > + * Returns an address, which the caller must kfree, containing > + * a duplicate of the passed string with leading and/or trailing > + * whitespace (as defined by isspace) removed. > + */ > +char *kstrimdup(const char *s, gfp_t gfp) > +{ > + char *buf; > + char *begin = skip_spaces(s); This could be const. > + size_t len = strlen(begin); > + > + while (len && isspace(begin[len - 1])) > + len--; > + > + buf = kmalloc_track_caller(len + 1, gfp); > + if (!buf) > + return NULL; > + > + memcpy(buf, begin, len); > + buf[len] = '\0'; > + > + return buf; > +} > +EXPORT_SYMBOL(kstrimdup); > + > +/** > * kmemdup - duplicate region of memory > * > * @src: memory region to duplicate -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>