* getopt_long_only bug
@ 2018-04-26 10:46 Szabolcs Nagy
2018-04-26 14:50 ` Rich Felker
0 siblings, 1 reply; 3+ messages in thread
From: Szabolcs Nagy @ 2018-04-26 10:46 UTC (permalink / raw)
To: musl
i got the following bug report:
$ cat a.c
#include <stdio.h>
#include <getopt.h>
int main()
{
struct option lo[] =
{
{"emit-relocs", no_argument, NULL, 'q'},
{"qmagic", no_argument, NULL, 'Q'},
{ 0 }
};
int li = -1;
char* a[] = { "", "-q", NULL };
int c = getopt_long_only(2, a, "q", lo, &li);
printf("c=%c/%i\n", c, c);
return 0;
}
$ ./a.musl
c=Q/81
$ ./a.glibc
c=q/113
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: getopt_long_only bug
2018-04-26 10:46 getopt_long_only bug Szabolcs Nagy
@ 2018-04-26 14:50 ` Rich Felker
2018-04-26 20:17 ` Szabolcs Nagy
0 siblings, 1 reply; 3+ messages in thread
From: Rich Felker @ 2018-04-26 14:50 UTC (permalink / raw)
To: musl
[-- Attachment #1: Type: text/plain, Size: 1131 bytes --]
On Thu, Apr 26, 2018 at 12:46:31PM +0200, Szabolcs Nagy wrote:
> i got the following bug report:
>
> $ cat a.c
> #include <stdio.h>
> #include <getopt.h>
>
> int main()
> {
> struct option lo[] =
> {
> {"emit-relocs", no_argument, NULL, 'q'},
> {"qmagic", no_argument, NULL, 'Q'},
> { 0 }
> };
>
> int li = -1;
> char* a[] = { "", "-q", NULL };
> int c = getopt_long_only(2, a, "q", lo, &li);
>
> printf("c=%c/%i\n", c, c);
>
> return 0;
> }
> $ ./a.musl
> c=Q/81
> $ ./a.glibc
> c=q/113
OK, this is a weird corner case. Apparently when in longonly mode,
short options need to be counted in addition to long ones for
determining if a partial match is unique.
The attached patch should solve the problem. Any review/comments would
be helpful. It uses an ugly inline strstr of sorts, because to use
strstr we'd need to copy to a temp buffer, and we wouldn't even
benefit since the string being searched is so short (usually 1 byte,
at most 4). The only reason it's there at all is because we committed
to supporting multibyte option chars in getopt.c so getopt_long_only
needs to handle them consistently.
Rich
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diff --git a/src/misc/getopt_long.c b/src/misc/getopt_long.c
index 008b747..ddcef94 100644
--- a/src/misc/getopt_long.c
+++ b/src/misc/getopt_long.c
@@ -1,5 +1,7 @@
#define _GNU_SOURCE
#include <stddef.h>
+#include <stdlib.h>
+#include <limits.h>
#include <getopt.h>
#include <stdio.h>
#include <string.h>
@@ -58,10 +60,10 @@ static int __getopt_long_core(int argc, char *const *argv, const char *optstring
{
int colon = optstring[optstring[0]=='+'||optstring[0]=='-']==':';
int i, cnt, match;
- char *arg, *opt;
+ char *arg, *opt, *start = argv[optind]+1;
for (cnt=i=0; longopts[i].name; i++) {
const char *name = longopts[i].name;
- opt = argv[optind]+1;
+ opt = start;
if (*opt == '-') opt++;
while (*opt && *opt != '=' && *opt == *name)
name++, opt++;
@@ -74,6 +76,17 @@ static int __getopt_long_core(int argc, char *const *argv, const char *optstring
}
cnt++;
}
+ if (cnt==1 && longonly && arg-start == mblen(start, MB_LEN_MAX)) {
+ int l = arg-start;
+ for (i=0; optstring[i]; i++) {
+ int j;
+ for (j=0; j<l && start[j]==optstring[i+j]; j++);
+ if (j==l) {
+ cnt++;
+ break;
+ }
+ }
+ }
if (cnt==1) {
i = match;
opt = arg;
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: getopt_long_only bug
2018-04-26 14:50 ` Rich Felker
@ 2018-04-26 20:17 ` Szabolcs Nagy
0 siblings, 0 replies; 3+ messages in thread
From: Szabolcs Nagy @ 2018-04-26 20:17 UTC (permalink / raw)
To: musl
* Rich Felker <dalias@libc.org> [2018-04-26 10:50:37 -0400]:
> OK, this is a weird corner case. Apparently when in longonly mode,
> short options need to be counted in addition to long ones for
> determining if a partial match is unique.
>
> The attached patch should solve the problem. Any review/comments would
> be helpful. It uses an ugly inline strstr of sorts, because to use
> strstr we'd need to copy to a temp buffer, and we wouldn't even
> benefit since the string being searched is so short (usually 1 byte,
> at most 4). The only reason it's there at all is because we committed
> to supporting multibyte option chars in getopt.c so getopt_long_only
> needs to handle them consistently.
looks ok to me.
> diff --git a/src/misc/getopt_long.c b/src/misc/getopt_long.c
> index 008b747..ddcef94 100644
> --- a/src/misc/getopt_long.c
> +++ b/src/misc/getopt_long.c
> @@ -1,5 +1,7 @@
> #define _GNU_SOURCE
> #include <stddef.h>
> +#include <stdlib.h>
> +#include <limits.h>
> #include <getopt.h>
> #include <stdio.h>
> #include <string.h>
> @@ -58,10 +60,10 @@ static int __getopt_long_core(int argc, char *const *argv, const char *optstring
> {
> int colon = optstring[optstring[0]=='+'||optstring[0]=='-']==':';
> int i, cnt, match;
> - char *arg, *opt;
> + char *arg, *opt, *start = argv[optind]+1;
> for (cnt=i=0; longopts[i].name; i++) {
> const char *name = longopts[i].name;
> - opt = argv[optind]+1;
> + opt = start;
> if (*opt == '-') opt++;
> while (*opt && *opt != '=' && *opt == *name)
> name++, opt++;
> @@ -74,6 +76,17 @@ static int __getopt_long_core(int argc, char *const *argv, const char *optstring
> }
> cnt++;
> }
> + if (cnt==1 && longonly && arg-start == mblen(start, MB_LEN_MAX)) {
> + int l = arg-start;
> + for (i=0; optstring[i]; i++) {
> + int j;
> + for (j=0; j<l && start[j]==optstring[i+j]; j++);
> + if (j==l) {
> + cnt++;
> + break;
> + }
> + }
> + }
> if (cnt==1) {
> i = match;
> opt = arg;
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-04-26 20:17 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2018-04-26 10:46 getopt_long_only bug Szabolcs Nagy
2018-04-26 14:50 ` Rich Felker
2018-04-26 20:17 ` Szabolcs Nagy
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