linux - Copy stdout contents to a file in command line mode -

i have program this. in terminal mode. want copy outptu contents file. first tried redirecting, didnt work due buffering. tried unbuffer command. didnt work correctly cases below

file

main() {         int i;         printf("starting\n");         scanf("%d",&i);         printf("the value %d\n",i); } 

output

# ./a.out  starting 4 value 4 

output unbuffer command

# unbuffer ./a.out | tee tt starting 4   ^c 

output simple redirection [works order of output not correct]

# ./a.out | tee tt 5 starting value 5 

i want contents shown in screen directly copied file. working in terminal mode [no gui].

unbuffer doesn't read standard input @ default, program waits without ever getting input. can make read , pass on standard input -p option:

unbuffer -p ./a.out | tee tt 

will work. downside doesn't display type write.

alternatively, if control c program, can disable default buffering of standard output when it's not terminal. can use, e.g., setbuf:

setbuf(stdout, null); 

or manually flush after each output.