Improve: cxx/ClassSys.cxx:classSysGetOwnPath(): for _Termux_, use procfs to return our true path.

[SwuduSusuwu]

virusAnalysisTests() uses ClassPortableExecutable() to load this, with the result that tests on Termux now always output the same offset+hash (since /proc/self/exe is /apex/com.android.runtime/bin/linker64).

Rationale: This would explain how (up until commit ?virusAnalysisTests(): if Linux, use procfs:@5f0ffd8), with each build, virusAnalysisTests()'s results showed a new offset+hash (

[./cxx/VirusAnalysis.cxx:239: Notice: signatureAnalysis(/*.file =*/ "/data/data/com.termux/files/home/SubStack/bin/a.out", /*.fileHash =*/ 0x1f2bcd741eb53ad61d715876794f04bf1bcdff63d2a03b2d78ec1283abd323d0) {return virusAnalysisAbort;} /* due to signature 0x74657374 found at offset=173170. You should treat this as a virus detection if this was not a test. */]
[./cxx/VirusAnalysis.cxx:240: Notice: signatureAnalysis(/*.file =*/ "/data/data/com.termux/files/home/SubStack/bin/a.out", /*.fileHash =*/ 0x96ac658655c1d9af12133771cdb0a22370ee6da84c4c76c0a665ced3c8f320ae) {return virusAnalysisAbort;} /* due to signature 0x74657374 found at offset=174578. You should treat this as a virus detection if this was not a test. */]

,) as opposed to the post-procfs outputs (

[./cxx/VirusAnalysis.cxx:243: Notice: signatureAnalysis(/*.file =*/ "/proc/self/exe", /*.fileHash =*/ 0x1e5b58a58065fd4863e2a84d0f418516ed8e91ce785f1a5a73741313123d82f7) {return virusAnalysisAbort;} /* due to signature 0x74657374 found at offset=20280. You should treat this as a virus detection if this was not a test. */]
[./cxx/VirusAnalysis.cxx:240: Notice: signatureAnalysis(/*.file =*/ "/proc/self/exe", /*.fileHash =*/ 0x1e5b58a58065fd4863e2a84d0f418516ed8e91ce785f1a5a73741313123d82f7) {return virusAnalysisAbort;} /* due to signature 0x74657374 found at offset=20280. You should treat this as a virus detection if this was not a test. */

) which use the /proc/self/exe path (and always give the same offset+hash.)
Use of the which linker64 path gives those results too:

[./cxx/VirusAnalysis.cxx:240: Notice: signatureAnalysis(/*.file =*/ "/apex/com.android.runtime/bin/linker64", /*.fileHash =*/ 0x1e5b58a58065fd4863e2a84d0f418516ed8e91ce785f1a5a73741313123d82f7) {return virusAnalysisAbort;} /* due to signature 0x74657374 found at offset=20280. You should treat this as a virus detection if this was not a test. */]

, thus am sure that this is due to how Termux loads all executables through linker64.
Have not labelled this as regression since all it does is cause one of the unit tests to print unexpected results for offset+hash (which does not alter the unit test's return value).
Local tests show that if you use readlink or realpath, you get the true path.
It was GitHub's code scan (https://github.com/SwuduSusuwu/SubStack/security/code-scanning/1277) which prompted the switch from argv[0] to /proc/self/exe at 5f0ffd8

[SwuduSusuwu]

It was issue #25 (commit d50262f) which moved /proc/self/exe into the new function classSysGetOwnPath() (which has other routes; if Windows, GetModulePathName(), if unknown system, argv[0]).

[SwuduSusuwu]

The use of loader64 to execute all programs was due to Google's rules.
Note that this just affects Termux from Google Store; the open source Termux has a normal loader such that /proc/self/exe acts as argv[0].

[SwuduSusuwu]

StackOverflow says stdio.h has PATH_MAX; auto build failed since GitHub's runner does not have PATH_MAX from such #include.
Since commits which fail to build cannot use git bisect, f331489 was replaced with af5226c (which has #include "limits.h" /* PATH_MAX */) which closes this.

If you used git pull in the short temporal window with f331489, just execute git pull --rebase (so that you tip is now af5226c)