On Wed, Mar 09 2022, Junio C Hamano wrote:
> Eric Sunshine <sunshine@xxxxxxxxxxxxxx> writes:
>
>> On Tue, Mar 8, 2022 at 6:58 PM Eric Sunshine <sunshine@xxxxxxxxxxxxxx> wrote:
>>> On Tue, Mar 8, 2022 at 6:55 PM Eric Sunshine <sunshine@xxxxxxxxxxxxxx> wrote:
>>> > On Tue, Mar 8, 2022 at 6:44 PM Carlo Marcelo Arenas Belón
>>> > <carenas@xxxxxxxxx> wrote:
>>> > > + local _GLIBC_VERSION=$(getconf GNU_LIBC_VERSION 2>/dev/null)
>>> > > + if echo "$_GLIBC_VERSION" | cut -d. -f1-2 |
>>> > > + awk '{ if ($2 - 2.34 < 0) exit 1 }'
>>> >
>>> > No need for `cut` since `awk` can accomplish the same by itself.
>>> >
>>> > if echo "$_GLIBC_VERSION" | awk '/^glibc / { if ($2 - 2.34 < 0) exit 1 }'
>>> >
>>> > should work, I would think.
>>>
>>> Nevermind, I forgot you want to better support "2.34.9000" matches.
>>> Though, awk should still be able to do so on its own, one would
>>> expect, but not too important.
>>
>> This seems to work, though it's getting a bit verbose:
>>
>> awk '/^glibc / { split($2,v,"."); if (sprintf("%s.%s", v[1], v[2])
>> - 2.34 < 0) exit 1 }'
>
> If we are losing "cut" (which I think is a good thing to do), we
> probably can lose the pipe, too and refer to $_GLIBC_VERSION as an
> element in ARGV[] and make the command used as "if" condition to a
> single "awk" script?
>
> In general it is a good discipline to question a pipeline that
> preprocesses input fed to a script written in a language with full
> programming power like awk and perl (and to lessor extent, sed) to
> see if we can come up with a simpler solution without pipeline
> helping to solve what these languages are invented to solve, and I
> very much appreciate your exploration ;-)
I agree :) But the first language we've got here is C. Rather than
fiddle around with getconf, awk/sed etc. why not just the rather
trivial:
diff --git a/Makefile b/Makefile
index 6f0b4b775fe..f566c9c5df2 100644
--- a/Makefile
+++ b/Makefile
@@ -732,6 +732,7 @@ TEST_BUILTINS_OBJS += test-parse-pathspec-file.o
TEST_BUILTINS_OBJS += test-partial-clone.o
TEST_BUILTINS_OBJS += test-path-utils.o
TEST_BUILTINS_OBJS += test-pcre2-config.o
+TEST_BUILTINS_OBJS += test-glibc-config.o
TEST_BUILTINS_OBJS += test-pkt-line.o
TEST_BUILTINS_OBJS += test-prio-queue.o
TEST_BUILTINS_OBJS += test-proc-receive.o
diff --git a/t/helper/test-glibc-config.c b/t/helper/test-glibc-config.c
new file mode 100644
index 00000000000..3c3cc2a8ba5
--- /dev/null
+++ b/t/helper/test-glibc-config.c
@@ -0,0 +1,12 @@
+#include "test-tool.h"
+#include "cache.h"
+
+int cmd__glibc_config(int argc, const char **argv)
+{
+#ifdef __GNU_LIBRARY__
+ printf("%d\n%d\n", __GLIBC__, __GLIBC_MINOR__);
+ return 0;
+#else
+ return 1;
+#endif
+}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index e6ec69cf326..c01422f5cab 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -35,6 +35,7 @@ static struct test_cmd cmds[] = {
{ "genrandom", cmd__genrandom },
{ "genzeros", cmd__genzeros },
{ "getcwd", cmd__getcwd },
+ { "glibc-config", cmd__glibc_config },
{ "hashmap", cmd__hashmap },
{ "hash-speed", cmd__hash_speed },
{ "index-version", cmd__index_version },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index 20756eefdda..dc061bc7833 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -26,6 +26,7 @@ int cmd__fast_rebase(int argc, const char **argv);
int cmd__genrandom(int argc, const char **argv);
int cmd__genzeros(int argc, const char **argv);
int cmd__getcwd(int argc, const char **argv);
+int cmd__glibc_config(int argc, const char **argv);
int cmd__hashmap(int argc, const char **argv);
int cmd__hash_speed(int argc, const char **argv);
int cmd__index_version(int argc, const char **argv);
I mainly copied the pcre2-config template I added in 95ca1f987ed
(grep/pcre2: better support invalid UTF-8 haystacks, 2021-01-24), which
likewise would have been quite a bit more complex to do from non-C.
