[PATCH] cmp: add KMG suffix for cmp -n MAXCOUNT

[Denys Vlasenko]

Applied, thank you.

On Thu, Jul 2, 2026 at 7:32 PM Anubhav Kokane via busybox
<busybox at busybox.net> wrote:
>
> Change input to getopt32 from int to char * so that
> max_count is parsed as string. Use xatol_sfx to convert
> string to long.
>
> function                                             old     new   delta
> cmp_main                                             616     661     +45
> xatoll_sfx                                             -      32     +32
> .rodata                                           101897  101896      -1
> ------------------------------------------------------------------------------
> (add/remove: 1/0 grow/shrink: 1/1 up/down: 77/-1)              Total: 76 bytes
>
> Signed-off-by: Anubhav Kokane <dev.anubhavk at gmail.com>
> ---
>  editors/cmp.c       | 13 ++++++++-----
>  testsuite/cmp.tests | 27 +++++++++++++++++++++++++++
>  2 files changed, 35 insertions(+), 5 deletions(-)
>
> diff --git a/editors/cmp.c b/editors/cmp.c
> index 6afd4029b..e57a60efa 100644
> --- a/editors/cmp.c
> +++ b/editors/cmp.c
> @@ -44,7 +44,7 @@ static const char fmt_differ[] ALIGN1 = "%s %s differ: byte %llu, line %u\n";
>  // This fmt_l_opt is gnu-ism. SUSv3 is "%.0s%.0s%llu %o %o\n"
>  static const char fmt_l_opt[] ALIGN1 = "%.0s%.0s%llu %3o %3o\n";
>
> -#define OPT_STR "sln:+"
> +#define OPT_STR "sln:"
>  #define CMP_OPT_s (1<<0)
>  #define CMP_OPT_l (1<<1)
>  #define CMP_OPT_n (1<<2)
> @@ -60,7 +60,8 @@ int cmp_main(int argc UNUSED_PARAM, char **argv)
>         int c1, c2;
>         unsigned opt;
>         int retval = 0;
> -       int max_count = -1;
> +       long int max_count = -1;
> +       char *max_count_str = NULL;
>
>  #if !ENABLE_LONG_OPTS
>         opt = getopt32(argv, "^"
> @@ -69,8 +70,7 @@ int cmp_main(int argc UNUSED_PARAM, char **argv)
>                         IF_DESKTOP(":?4")
>                         IF_NOT_DESKTOP(":?2")
>                         ":l--s:s--l",
> -//TODO: -n MAXCOUNT should allow KMG suffixes
> -                       &max_count
> +                       &max_count_str
>         );
>  #else
>         static const char cmp_longopts[] ALIGN1 =
> @@ -86,7 +86,7 @@ int cmp_main(int argc UNUSED_PARAM, char **argv)
>                         IF_NOT_DESKTOP(":?2")
>                         ":l--s:s--l",
>                         cmp_longopts,
> -                       &max_count
> +                       &max_count_str
>         );
>  #endif
>         argv += optind;
> @@ -101,6 +101,9 @@ int cmp_main(int argc UNUSED_PARAM, char **argv)
>                         }
>                 }
>         }
> +
> +       if (opt & CMP_OPT_n)
> +               max_count = xatol_sfx(max_count_str, kmg_i_suffixes);
>
>         xfunc_error_retval = 2;  /* missing file results in exitcode 2 */
>         if (opt & CMP_OPT_s)
> diff --git a/testsuite/cmp.tests b/testsuite/cmp.tests
> index 6711dbede..42122a4df 100755
> --- a/testsuite/cmp.tests
> +++ b/testsuite/cmp.tests
> @@ -29,6 +29,22 @@ testing "cmp -n2" \
>         "foo" \
>         "bar"
>
> +testing "cmp -n2k" \
> +       'cmp -n2k - input; echo $?' \
> +"- input differ: byte 1, line 1
> +1
> +" \
> +       "foo" \
> +       "bar"
> +
> +testing "cmp -n 1g" \
> +       'cmp -n 1g - input; echo $?' \
> +"- input differ: byte 1, line 1
> +1
> +" \
> +       "foo" \
> +       "bar"
> +
>  testing "cmp -ln2" \
>         'cmp -ln2 - input; echo $?' \
>  "\
> @@ -39,6 +55,17 @@ testing "cmp -ln2" \
>         "foo" \
>         "bar"
>
> +testing "cmp -ln2M" \
> +       'cmp -ln2M - input; echo $?' \
> +"\
> +1 142 146
> +2 141 157
> +3 162 157
> +1
> +" \
> +       "foo" \
> +       "bar"
> +
>  optional DESKTOP
>  testing "cmp -ln2 SKIP1 SKIP2 " \
>         'cmp -ln2 - input 1 1; echo $?' \
> --
> 2.43.0
>
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