in c system() executes before printf() even when printf come first [duplicate]

Question

This question already has an answer here: C/Unix Strange behaviour while using system calls and printf (1 answer) Closed 3 years ago. I just started using the system() function in c, and I thought of starting the same executable from within it self using the system function, so I wrote the following program #include #include int main() { printf("some string"); system("./a.out"); } -I used gcc to compile it- when I ran the program it did not print anything, it just kept going until I used the shortcut ctrl-c to stop the execution,then it started printing the output(it did not print anything until I stopped it) I believe the statements should execute sequentially, why did it not print anything until I stopped it? JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

By default, when stdoutis connected to a terminal, it is line-buffered. printf("some string"); doesn't have a '\n' in it and you aren't calling fflush(stdout); after it either, so all this printf("some string"); does is copy "some string" into your stdout's output buffer. The buffer is flushed as the end of main. printf("some string\n"); would flush the buffer immediately, provided stdout is connected to a terminal and you didn't change stdout's buffering. printf("some string"); fflush(stdout); will flush the buffer immediately regardless of context and without the need for the '\n'.