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https://github.com/arun11299/cpp-subprocess.git
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2ef9f168d3
It's useful to be able to know the exit code of the process when it fails with a non-zero exit code. To get this to work, I had to fix a bug in the implementation of check_output. Previously, check_output would call both `p.communicate()` and `p.poll()`. The former has the effect of waiting for EOF on the input and then waiting for the child to exit, reaping it with `waitpid(2)`. Unfortunately, `p.poll()` was hoping to be able to also use `waitpid(2)` to retrieve the exit code of the process. But since the child had already been reaped, the given pid no longer existed, and thus `waitpid(2)` would return `ECHILD`. Luckily the call to `p.poll()` is unnecessary, as the process already provides `p.retcode()` for retrieving the exit code.
52 lines
1.2 KiB
C++
52 lines
1.2 KiB
C++
#include <iostream>
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#include "../subprocess.hpp"
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namespace sp = subprocess;
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void test_ret_code()
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{
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std::cout << "Test::test_poll_ret_code" << std::endl;
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auto p = sp::Popen({"/usr/bin/false"});
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while (p.poll() == -1) {
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#ifndef _MSC_VER
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usleep(1000 * 100);
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#endif
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}
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assert (p.retcode() == 1);
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}
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void test_ret_code_comm()
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{
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using namespace sp;
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auto cat = Popen({"cat", "../subprocess.hpp"}, output{PIPE});
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auto grep = Popen({"grep", "template"}, input{cat.output()}, output{PIPE});
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auto cut = Popen({"cut", "-d,", "-f", "1"}, input{grep.output()}, output{PIPE});
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auto res = cut.communicate().first;
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std::cout << res.buf.data() << std::endl;
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std::cout << "retcode: " << cut.retcode() << std::endl;
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}
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void test_ret_code_check_output()
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{
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using namespace sp;
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bool caught = false;
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try {
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auto obuf = check_output({"/bin/false"}, shell{false});
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assert(false); // Expected to throw
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} catch (CalledProcessError &e) {
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std::cout << "retcode: " << e.retcode << std::endl;
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assert (e.retcode == 1);
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caught = true;
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}
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assert(caught);
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}
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int main() {
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// test_ret_code();
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test_ret_code_comm();
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test_ret_code_check_output();
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return 0;
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}
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