使用popen执行命令行出错

[weechatfly]

android的so中使用popen执行命令行会出错，代码如下：
char buf_ps[1024];
FILE *ptr;
string result("");
if((ptr=popen(“cat /proc/self/cmdline”, "r"))!=NULL)
{
while(fgets(buf_ps, 1024, ptr)!=NULL)
{
result.append(buf_ps);
}
pclose(ptr);
}
出错如下：
[12:08:20 719] ERROR [cn.banny.unidbg.linux.ARMSyscallHandler] (ARMSyscallHandler:852) - execve filename=/system/bin/sh, args=[sh, -c, cat /proc/self/cmdline], env=[]
[12:08:20 720] INFO [cn.banny.unidbg.linux.ARMSyscallHandler] (ARMSyscallHandler:1361) - exit with code: 127
java.lang.Exception: exit_group status=127
at cn.banny.unidbg.linux.ARMSyscallHandler.exit_group(ARMSyscallHandler.java:1361)
at cn.banny.unidbg.linux.ARMSyscallHandler.hook(ARMSyscallHandler.java:321)
at unicorn.Unicorn.invokeInterruptCallbacks(Unicorn.java:123)
at unicorn.Unicorn.emu_start(Native Method)
at cn.banny.unidbg.AbstractEmulator.emulate(AbstractEmulator.java:302)
at cn.banny.unidbg.AbstractEmulator.eFunc(AbstractEmulator.java:400)
at cn.banny.unidbg.arm.AbstractARMEmulator.eFunc(AbstractARMEmulator.java:205)
at cn.banny.unidbg.linux.LinuxModule.emulateFunction(LinuxModule.java:203)
at cn.banny.unidbg.linux.android.dvm.DvmClass.callStaticJniMethod(DvmClass.java:209)
at cn.banny.unidbg.android.dx.DxSoUtilTest.testRomxSdk(DxSoUtilTest.java:142)
at cn.banny.unidbg.android.dx.DxSoUtilTest.main(DxSoUtilTest.java:93)
[12:08:20 724] DEBUG [cn.banny.unidbg.AbstractEmulator] (AbstractEmulator:329) - emulate unicorn@0x4020afe9[libnative-lib.so]0xafe9 finished sp=unicorn@0xbfffdea8, offset=95ms

[zhkl0228]

`

private class MyAndroidARMEmulator extends AndroidARMEmulator {
@OverRide
protected UnixSyscallHandler createSyscallHandler(SvcMemory svcMemory) {
return new MyARMSyscallHandler(svcMemory);
}
}

private class MyARMSyscallHandler extends com.github.unidbg.linux.ARMSyscallHandler {
    public MyARMSyscallHandler(SvcMemory svcMemory) {
        super(svcMemory);
    }
    @Override
    protected boolean handleUnknownSyscall(Emulator emulator, int NR) {
        switch (NR) {
            case 114:
                wait4(emulator);
                return true;
            case 190:
                vfork(emulator);
                return true;
            case 359:
                pipe2(emulator);
                return true;
        }

        return super.handleUnknownSyscall(emulator, NR);
    }

    private void wait4(Emulator emulator) {
        EditableArm32RegisterContext context = emulator.getContext();
        int pid = context.getR0Int();
        Pointer wstatus = context.getR1Pointer();
        int options = context.getR2Int();
        Pointer rusage = context.getR3Pointer();
        System.out.println("wait4 pid=" + pid + ", wstatus=" + wstatus + ", options=0x" + Integer.toHexString(options) + ", rusage=" + rusage);
    }

    private void vfork(Emulator emulator) {
        EditableArm32RegisterContext context = emulator.getContext();
        int childPid = emulator.getPid() + ThreadLocalRandom.current().nextInt(256);
        int r0 = 0;
        if (parent) {
            r0 = childPid;
        }
        System.out.println("vfork pid=" + r0);
        context.setR0(r0);
    }

    private void pipe2(Emulator emulator) {
        EditableArm32RegisterContext context = emulator.getContext();
        Pointer pipefd = context.getPointerArg(0);
        int flags = context.getIntArg(1);
        int write = getMinFd();
        this.fdMap.put(write, new DumpFileIO(write));
        int read = getMinFd();
        String stdout = "com.ss.android.ugc.aweme\n"; // cat /proc/self/cmdline
        this.fdMap.put(read, new ByteArrayFileIO(0, "pipe2_read_side", stdout.getBytes()));
        pipefd.setInt(0, read);
        pipefd.setInt(4, write);
        System.out.println("pipe2 pipefd=" + pipefd + ", flags=0x" + flags + ", read=" + read + ", write=" + write + ", stdout=" + stdout);
        context.setR0(0);
    }
}`