1

我有问题_popen(const char *, const char *)

我正在尝试使用 awk 从 adb 获取信息，但我的程序在第二次 _popen 调用时崩溃（该方法被调用两次）。

这是有问题的代码（sysinf_getvalue()在主程序中被多次调用）。

丑陋的代码

int deviceadbinfowritten = 0;
int devicebootloaderinfowritten = 0;
int adbinit = 0;

int initadb()
{
    if(!adbinit)
    {
        system("adb kill-server && adb start-server");
        adbinit = 1;
    }
    return 0;
}

int sysinfo_getadbinfofile()
{
    if(!deviceadbinfowritten)
    {
        system("echo Please connect your device && adb wait-for-device && adb.exe shell getprop > deviceinfo");
        deviceadbinfowritten = 1;
    }

    return 0;
}

int sysinfo_getbootloaderinfofile()
{
    if(!devicebootloaderinfowritten)
    {
        system("adb wait-for-device && adb reboot bootloader && fastboot getvar all > bootloaderinfo && fastboot reboot");
        devicebootloaderinfowritten = 1;
    }
    return 0;
}

char *sysinfo_getvalue(char *key, int bootloader)
{
    initadb();
    if(bootloader) sysinfo_getbootloaderinfofile();
    else sysinfo_getadbinfofile();
    char *file = (bootloader)?"bootloaderinfo":"deviceinfo";

    char *command = malloc(sizeof(char) * (strlen("awk.exe -F\":\" \" { print $2 }\" < ") + strlen(key) + (bootloader)?0:2 + strlen(file)));
    char *adbkey = malloc((strlen(key)+2)* (sizeof(char)));
    if(!bootloader) sprintf(adbkey, "/%s/", key);
    sprintf(command, "awk.exe -F\":\" \"%s { print $2 }\" < %s", ((bootloader)?key:adbkey), file);

    printf("%s\n", command);
    char *pointer = exe(command);
    if(!bootloader)
    {
        pointer += 2;
        pointer[strlen(pointer)-3] = 0;
    }

    return pointer;
}

char *exe(char *exe)
{
    char buffer[1024];
    FILE *f;

    printf("debug %s\n", exe);

    f = _popen(exe, "r");

    printf("debug\n");

    char *res = NULL;

    printf("debug\n");

    if (f == NULL) {
        printf("[-] Failed to run command\n" );
        return NULL;
}
    printf("debug\n");

    while (fgets(buffer, sizeof(buffer), f) != NULL) {
        if(res == NULL) {res = malloc(strlen(buffer) * sizeof(char)); strcpy(res, buffer);}
        else {res = realloc(res, strlen(res) * sizeof(char) + sizeof(buffer));sprintf(res, "%s%s", res, buffer);}
}

    printf("debug\n");

    _pclose(f);

    return res;
}

注意：如果我exe()使用提供的相同字符串直接调用 main _popen 不会崩溃。

注2：调试器说"warning: HEAP[program.exe]: warning: Heap block at 002D2EC0 modified at 002D2EC9 past requested size of 1"

4

2 回答 2

1

It looks as if you are missing to allocate room for the 0-terminator.

That is the one last additional byte every character array needs if used as string to indicate the end of the string by a character of value NUL (decimal 0).

At least this line:

char *command = malloc(sizeof(char) * (strlen("awk.exe -F\":\" \" { print $2 }\" < ") + strlen(key) + (bootloader)?0:2 + strlen(file)));

shall allocate one character more:

char *command = malloc(
  sizeof(char) * (
    strlen("awk.exe -F\":\" \" { print $2 }\" < ") + 
    strlen(key) + 
    (bootloader)?0:2 + strlen(file)) + 
    1
  )
);

(I did not check all allocations/delcaration of character arrays in your code, for issues like this.)

于 2013-01-20T12:39:22.313 回答
0

我在此链接中发现C++ system() not working 当两个不同的参数中有空格时，如果您希望它们正常工作，您需要用引号将所有系统调用封装起来。例如在我的代码中我需要使用exe("\"mycommand\"");而不是exe("mycommand");

于 2013-01-21T18:04:56.120 回答