CODEWITHSUNDEEP
c++cmdgrep
vidhya
vidhya

Reputation: 5

C++: Output file of system command not generated

I am trying to run a shell command from my code. However, the output file (ts.dat) is not generated. Can somebody let me know how to solve this problem?

string cmd1, input;
cout << "Enter the input file name: ";
cin >> input;

cmd1 = "grep 'DYNA>' input | cut -c9-14 > ts.dat";
system((cmd1).c_str());

Upvotes: 1

Views: 106

Answers (2)

Aiman Al-Eryani
Aiman Al-Eryani

Reputation: 709

cmd1="grep 'DYNA>' "+input+" | cut -c9-14 > ts.dat";

Placing input inside the quotes will let the compiler parse it as a string instead of a variable.

Upvotes: 1

pstrjds
pstrjds

Reputation: 17428

Edit this line:

cmd1="grep 'DYNA>' input | cut -c9-14 > ts.dat";

To this:

cmd1="grep 'DYNA>' " + input + " | cut -c9-14 > ts.dat";

You need to actually use the value from the input string. The way you have your code currently, you are just writing the word input in your string and not using the value that is stored in the string.

Upvotes: 1

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