Input / Output Redirection…!!! Presented By :- Akash Patel
Input / Output Redirection
Presented By :- Akash Patel
Three standard file descriptors :-
1. stdin 0 – Standard input to the program.
2. stdout 1 – Standard output from the program.
3. stderr 2 – Standard error output from the program.
Purpose & Command :-
1) redirect std output to filename:- > filename or 1> filename
2) append std out to filename:- >> filename
3) append std out and std error to filename :- >> filename 2>&1 or 1>> filename 2>&1
4) take input from filename :- < filename or 0 < filename
5) redirect std error to filename :- 2> filename
6) redirect std out and std error to filename :- 1> filename 2>&1 or > filename 2>&1
Some examples of using I/O redirection :-
1. Simple output _ errors :-
2. Output in file _ error in display :-
3. Appending output in file :-
4. Redirect errors in file :-
5. Append errors as previous :-
6. Discarding errors _ send to null=0 :-
7. Save output _ error in one file :-
8. Save output _ error in seprate file :-
