[1/2] Introduce strtosz_suffix()

From: Jes Sorensen <Jes.Sorensen@redhat.com>

This introduces strtosz_suffix() which allows the caller to specify a
default suffix in case the non default of MB is wanted.

strtosz() is kept as a wrapper for strtosz_suffix() which keeps it's
current default of MB.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
---
 cutils.c      |   17 ++++++++++++++---
 qemu-common.h |    7 +++++++
 2 files changed, 21 insertions(+), 3 deletions(-)

Sorry for the late review.

Jes.Sorensen@redhat.com writes:

> From: Jes Sorensen <Jes.Sorensen@redhat.com>
>
> This introduces strtosz_suffix() which allows the caller to specify a
> default suffix in case the non default of MB is wanted.
>
> strtosz() is kept as a wrapper for strtosz_suffix() which keeps it's
> current default of MB.
>
> Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
> ---
>  cutils.c      |   17 ++++++++++++++---
>  qemu-common.h |    7 +++++++
>  2 files changed, 21 insertions(+), 3 deletions(-)
>
> diff --git a/cutils.c b/cutils.c
> index 28089aa..7984bc1 100644
> --- a/cutils.c
> +++ b/cutils.c
> @@ -291,10 +291,10 @@ int fcntl_setfl(int fd, int flag)
>   * value must be terminated by whitespace, ',' or '\0'. Return -1 on
>   * error.
>   */
> -ssize_t strtosz(const char *nptr, char **end)
> +ssize_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)

Last parameter's const is of marginal uility.  Matter of taste.

>  {
>      ssize_t retval = -1;
> -    char *endptr, c;
> +    char *endptr, c, d;
>      int mul_required = 0;
>      double val, mul, integral, fraction;
>  
> @@ -313,10 +313,16 @@ ssize_t strtosz(const char *nptr, char **end)
>       * part of a multi token argument.
>       */
>      c = *endptr;
> +    d = c;
>      if (isspace(c) || c == '\0' || c == ',') {
>          c = 0;
> +        if (default_suffix) {
> +            d = default_suffix;
> +        } else {
> +            d = c;
> +        }

The else clause "d = c" is effectively "d = 0" (due to prior "c = 0"),
which is the same as "d = default_suffix" (due to else's condition).
Thus, you can replace the conditional by a simple

    d = default_suffix;

>      }
> -    switch (c) {
> +    switch (d) {
>      case 'B':
>      case 'b':
>          mul = 1;
> @@ -371,3 +377,8 @@ fail:
>  
>      return retval;
>  }
> +
> +ssize_t strtosz(const char *nptr, char **end)
> +{
> +    return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
> +}
> diff --git a/qemu-common.h b/qemu-common.h
> index de82c2e..1ed32e5 100644
> --- a/qemu-common.h
> +++ b/qemu-common.h
> @@ -149,7 +149,14 @@ time_t mktimegm(struct tm *tm);
>  int qemu_fls(int i);
>  int qemu_fdatasync(int fd);
>  int fcntl_setfl(int fd, int flag);
> +
> +#define STRTOSZ_DEFSUFFIX_TB	'T'
> +#define STRTOSZ_DEFSUFFIX_GB	'G'
> +#define STRTOSZ_DEFSUFFIX_MB	'M'
> +#define STRTOSZ_DEFSUFFIX_KB	'K'
> +#define STRTOSZ_DEFSUFFIX_B	'B'

I don't see what these defines buy us over the literals, but if it makes
you or other reviewers happier...

>  ssize_t strtosz(const char *nptr, char **end);
> +ssize_t strtosz_suffix(const char *nptr, char **end, const char default_suffix);
>  
>  /* path.c */
>  void init_paths(const char *prefix);