v0.40: Create exercises. Challenge the community.

stream_mask

Your mission

Write a program that copies standard input to standard output while masking a chosen byte sequence.

See it in action

printf 'alpha beta alpha\n' | ./stream_mask alpha | cat -e

Expected result

***** beta *****$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly one non-empty argument (argc must be 2): the token to mask.
Read all data from standard input until end of file.
Every non-overlapping occurrence of the token must be replaced by the same number of * characters.
All other bytes must be written unchanged, including spaces and newlines.
If a read or allocation error happens, write an error message to standard error and return 1.
If the argument count is wrong or the token is empty, return 1.

More examples

printf 'aaaaa' | ./stream_mask aa | cat -e

Expected result

****a

Constraints

Expected files

stream_mask.c

Allowed functions

readwritestrlenmemmemmemmovemalloccallocreallocfreeprintffprintfperror

stream_mask

Files and streams

Your mission

Write a program that copies standard input to standard output while masking a chosen byte sequence.

See it in action

printf 'alpha beta alpha\n' | ./stream_mask alpha | cat -e

Expected result

***** beta *****$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly one non-empty argument (argc must be 2): the token to mask.
Read all data from standard input until end of file.
Every non-overlapping occurrence of the token must be replaced by the same number of * characters.
All other bytes must be written unchanged, including spaces and newlines.
If a read or allocation error happens, write an error message to standard error and return 1.
If the argument count is wrong or the token is empty, return 1.

More examples

printf 'aaaaa' | ./stream_mask aa | cat -e

Expected result

****a

Constraints

Expected files

stream_mask.c

Allowed functions

readwritestrlenmemmemmemmovemalloccallocreallocfreeprintffprintfperror

Tests

Run the tests to grade your code

Build your code, then check each test here. Open a result to inspect its output.

Build

01Repeated tokenWaiting

02A space byte can be maskedWaiting

03Newlines are preservedWaiting

04No matching tokenWaiting

05Empty inputWaiting

06Empty tokenWaiting

07Missing argumentWaiting

08Too many argumentsWaiting

09Non-overlapping matchesWaiting

stream_mask

Your mission

Write a program that copies standard input to standard output while masking a chosen byte sequence.

See it in action

printf 'alpha beta alpha\n' | ./stream_mask alpha | cat -e

Expected result

***** beta *****$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly one non-empty argument (argc must be 2): the token to mask.
Read all data from standard input until end of file.
Every non-overlapping occurrence of the token must be replaced by the same number of * characters.
All other bytes must be written unchanged, including spaces and newlines.
If a read or allocation error happens, write an error message to standard error and return 1.
If the argument count is wrong or the token is empty, return 1.

More examples

printf 'aaaaa' | ./stream_mask aa | cat -e

Expected result

****a

Constraints

Expected files

stream_mask.c

Allowed functions

readwritestrlenmemmemmemmovemalloccallocreallocfreeprintffprintfperror

v0.40: Create exercises. Challenge the community.

Meet Studio →

stream_mask

Files and streams

Your mission

Write a program that copies standard input to standard output while masking a chosen byte sequence.

See it in action

printf 'alpha beta alpha\n' | ./stream_mask alpha | cat -e

Expected result

***** beta *****$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly one non-empty argument (argc must be 2): the token to mask.
Read all data from standard input until end of file.
Every non-overlapping occurrence of the token must be replaced by the same number of * characters.
All other bytes must be written unchanged, including spaces and newlines.
If a read or allocation error happens, write an error message to standard error and return 1.
If the argument count is wrong or the token is empty, return 1.

More examples

printf 'aaaaa' | ./stream_mask aa | cat -e

Expected result

****a

Constraints

Expected files

stream_mask.c

Allowed functions

readwritestrlenmemmemmemmovemalloccallocreallocfreeprintffprintfperror

Tests

Run the tests to grade your code

Build your code, then check each test here. Open a result to inspect its output.

Build

01Repeated tokenWaiting

02A space byte can be maskedWaiting

03Newlines are preservedWaiting

04No matching tokenWaiting

05Empty inputWaiting

06Empty tokenWaiting

07Missing argumentWaiting

08Too many argumentsWaiting

09Non-overlapping matchesWaiting