#define won't work in QStringList , gives no error

[Lost User]

1. Why putting #define in char "string" won't process the "command" to "start a new process" , however, compiler is not giving an error ? In debug mode I have literal BT_DATABASE_TEST in "command", 2. I need to make the primary text (*.txt) file a variable - how ?

#define BT_DATABASE_TEST "../../BT_DATABASE/BluetoothDatabase.txt"
const char *command = "bluetoothctl show | tee ../../BT_DATABASE/BluetoothDatabase.txt | tee /tmp/temp";
//const char *command = "bluetoothctl show | tee BT_DATABASE_TEST | tee /tmp/temp"; won't work
QP->start("/bin/sh", QStringList() << "-c" << command);

[Mircea Neacsu]

1. You can concatenate strings. Like this:

#define BT_DATABASE_TEST "../../BT_DATABASE/BluetoothDatabase.txt"
const char *command = "bluetoothctl show | tee " BT_DATABASE_TEXT " | tee /tmp/temp";

2. Maybe something like this:

std::string var = "blah_blah.txt";
std::string command = std::string("bluetoothctl show | tee ") + var + std::string("" | tee /tmp/temp");
QP->start("/bin/sh", QStringList() << "-c" << command.c_str());

Mircea

[David Crow]

Member 14968771 wrote:

1. Why putting #define in char "string"...

The preprocessor does not see #define directives inside string literals.

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

[Lost User]

Basically I can build a string then "convert it" to char, Neat trick. Thanks