v0.40: Create exercises. Challenge the community.

process_stream_open

Your mission

Implement process_stream_open, a small process launcher that exposes one end of a pipe.

See it in action

process_stream_open("printf", (char *const []){"printf", "ready\\n", NULL}, 'r')

Expected result

fd reading ready\n

Your checklist

For your own tracking. Tests grade your code.

Create process_stream_open.c.
Expose int process_stream_open(const char *file, char *const argv[], char mode);.
Launch file with argv through execvp in a child process.
When mode is 'r', return a file descriptor that reads from the child process standard output.
When mode is 'w', return a file descriptor that writes to the child process standard input.
Return -1 for invalid arguments, invalid mode, pipe failure, or fork failure.
Close every pipe end that is not needed in each process.
The parent must not wait for the child in this function.

More examples

process_stream_open("cat", (char *const []){"cat", NULL}, 'w')

Expected result

fd writing to child stdin

Constraints

Expected files

process_stream_open.c

Allowed functions

pipeforkdup2execvpcloseexit

process_stream_open

Processes and signals

Your mission

Implement process_stream_open, a small process launcher that exposes one end of a pipe.

See it in action

process_stream_open("printf", (char *const []){"printf", "ready\\n", NULL}, 'r')

Expected result

fd reading ready\n

Your checklist

For your own tracking. Tests grade your code.

Create process_stream_open.c.
Expose int process_stream_open(const char *file, char *const argv[], char mode);.
Launch file with argv through execvp in a child process.
When mode is 'r', return a file descriptor that reads from the child process standard output.
When mode is 'w', return a file descriptor that writes to the child process standard input.
Return -1 for invalid arguments, invalid mode, pipe failure, or fork failure.
Close every pipe end that is not needed in each process.
The parent must not wait for the child in this function.

More examples

process_stream_open("cat", (char *const []){"cat", NULL}, 'w')

Expected result

fd writing to child stdin

Constraints

Expected files

process_stream_open.c

Allowed functions

pipeforkdup2execvpcloseexit

Tests

Run the tests to grade your code

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

Build

01Invalid inputs return -1Waiting

02Read mode captures child stdoutWaiting

03Read mode works with argv commandsWaiting

04Write mode feeds child stdinWaiting

05Parent returns a pipe fd even when child exec fails laterWaiting

process_stream_open

Your mission

Implement process_stream_open, a small process launcher that exposes one end of a pipe.

See it in action

process_stream_open("printf", (char *const []){"printf", "ready\\n", NULL}, 'r')

Expected result

fd reading ready\n

Your checklist

For your own tracking. Tests grade your code.

Create process_stream_open.c.
Expose int process_stream_open(const char *file, char *const argv[], char mode);.
Launch file with argv through execvp in a child process.
When mode is 'r', return a file descriptor that reads from the child process standard output.
When mode is 'w', return a file descriptor that writes to the child process standard input.
Return -1 for invalid arguments, invalid mode, pipe failure, or fork failure.
Close every pipe end that is not needed in each process.
The parent must not wait for the child in this function.

More examples

process_stream_open("cat", (char *const []){"cat", NULL}, 'w')

Expected result

fd writing to child stdin

Constraints

Expected files

process_stream_open.c

Allowed functions

pipeforkdup2execvpcloseexit

v0.40: Create exercises. Challenge the community.

Meet Studio →

process_stream_open

Processes and signals

Your mission

Implement process_stream_open, a small process launcher that exposes one end of a pipe.

See it in action

process_stream_open("printf", (char *const []){"printf", "ready\\n", NULL}, 'r')

Expected result

fd reading ready\n

Your checklist

For your own tracking. Tests grade your code.

Create process_stream_open.c.
Expose int process_stream_open(const char *file, char *const argv[], char mode);.
Launch file with argv through execvp in a child process.
When mode is 'r', return a file descriptor that reads from the child process standard output.
When mode is 'w', return a file descriptor that writes to the child process standard input.
Return -1 for invalid arguments, invalid mode, pipe failure, or fork failure.
Close every pipe end that is not needed in each process.
The parent must not wait for the child in this function.

More examples

process_stream_open("cat", (char *const []){"cat", NULL}, 'w')

Expected result

fd writing to child stdin

Constraints

Expected files

process_stream_open.c

Allowed functions

pipeforkdup2execvpcloseexit

Tests

Run the tests to grade your code

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

Build

01Invalid inputs return -1Waiting

02Read mode captures child stdoutWaiting

03Read mode works with argv commandsWaiting

04Write mode feeds child stdinWaiting

05Parent returns a pipe fd even when child exec fails laterWaiting