v0.40: Create exercises. Challenge the community.

mini_scanf

Your mission

Implement mini_scanf, a reduced formatted input function that reads from standard input.

See it in action

standard input: `-17 bridge Z`, call `mini_scanf("%d %s %c", &n, word, &c)`

Expected result

returns 3, stores -17, `bridge`, and `Z`

Your checklist

For your own tracking. Tests grade your code.

Expose int mini_scanf(const char *format, ...); from mini_scanf.c.
Support only the conversions %s, %d, and %c.
Whitespace in the format string must consume any amount of whitespace from input.
%d and %s skip leading whitespace before reading their value.
%c reads exactly one byte and does not skip leading whitespace by itself.
Literal characters in the format must match the next input byte.
Return the number of successful conversions, or EOF only when input ends before any conversion is possible.

More examples

standard input: `xy z`, call `mini_scanf("%c%c%c", &a, &b, &c)`

Expected result

returns 3, stores `x`, `y`, then a space

Constraints

Expected files

mini_scanf.c

Allowed functions

fgetcungetcferrorfeofisspaceisdigitva_startva_argva_copyva_end

mini_scanf

Parsing and formats

Your mission

Implement mini_scanf, a reduced formatted input function that reads from standard input.

See it in action

standard input: `-17 bridge Z`, call `mini_scanf("%d %s %c", &n, word, &c)`

Expected result

returns 3, stores -17, `bridge`, and `Z`

Your checklist

For your own tracking. Tests grade your code.

Expose int mini_scanf(const char *format, ...); from mini_scanf.c.
Support only the conversions %s, %d, and %c.
Whitespace in the format string must consume any amount of whitespace from input.
%d and %s skip leading whitespace before reading their value.
%c reads exactly one byte and does not skip leading whitespace by itself.
Literal characters in the format must match the next input byte.
Return the number of successful conversions, or EOF only when input ends before any conversion is possible.

More examples

standard input: `xy z`, call `mini_scanf("%c%c%c", &a, &b, &c)`

Expected result

returns 3, stores `x`, `y`, then a space

Constraints

Expected files

mini_scanf.c

Allowed functions

fgetcungetcferrorfeofisspaceisdigitva_startva_argva_copyva_end

Tests

Run the tests to grade your code

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

Build

01Mixed conversionsWaiting

02Character conversion keeps spacesWaiting

03Literal text in the formatWaiting

04Failed integer conversionWaiting

05Whitespace skip and positive signWaiting

06Integer leaves the next byte for %cWaiting

07Literal mismatch stops after previous conversionWaiting

08%c reads whitespace bytesWaiting

09Empty input returns EOFWaiting

10Format whitespace consumes a full input run before %cWaiting

11Leading format whitespace skips input whitespaceWaiting

12Trailing format whitespace stops before the next non-space byteWaiting

mini_scanf

Your mission

Implement mini_scanf, a reduced formatted input function that reads from standard input.

See it in action

standard input: `-17 bridge Z`, call `mini_scanf("%d %s %c", &n, word, &c)`

Expected result

returns 3, stores -17, `bridge`, and `Z`

Your checklist

For your own tracking. Tests grade your code.

Expose int mini_scanf(const char *format, ...); from mini_scanf.c.
Support only the conversions %s, %d, and %c.
Whitespace in the format string must consume any amount of whitespace from input.
%d and %s skip leading whitespace before reading their value.
%c reads exactly one byte and does not skip leading whitespace by itself.
Literal characters in the format must match the next input byte.
Return the number of successful conversions, or EOF only when input ends before any conversion is possible.

More examples

standard input: `xy z`, call `mini_scanf("%c%c%c", &a, &b, &c)`

Expected result

returns 3, stores `x`, `y`, then a space

Constraints

Expected files

mini_scanf.c

Allowed functions

fgetcungetcferrorfeofisspaceisdigitva_startva_argva_copyva_end

v0.40: Create exercises. Challenge the community.

Meet Studio →

mini_scanf

Parsing and formats

Your mission

Implement mini_scanf, a reduced formatted input function that reads from standard input.

See it in action

standard input: `-17 bridge Z`, call `mini_scanf("%d %s %c", &n, word, &c)`

Expected result

returns 3, stores -17, `bridge`, and `Z`

Your checklist

For your own tracking. Tests grade your code.

Expose int mini_scanf(const char *format, ...); from mini_scanf.c.
Support only the conversions %s, %d, and %c.
Whitespace in the format string must consume any amount of whitespace from input.
%d and %s skip leading whitespace before reading their value.
%c reads exactly one byte and does not skip leading whitespace by itself.
Literal characters in the format must match the next input byte.
Return the number of successful conversions, or EOF only when input ends before any conversion is possible.

More examples

standard input: `xy z`, call `mini_scanf("%c%c%c", &a, &b, &c)`

Expected result

returns 3, stores `x`, `y`, then a space

Constraints

Expected files

mini_scanf.c

Allowed functions

fgetcungetcferrorfeofisspaceisdigitva_startva_argva_copyva_end

Tests

Run the tests to grade your code

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

Build

01Mixed conversionsWaiting

02Character conversion keeps spacesWaiting

03Literal text in the formatWaiting

04Failed integer conversionWaiting

05Whitespace skip and positive signWaiting

06Integer leaves the next byte for %cWaiting

07Literal mismatch stops after previous conversionWaiting

08%c reads whitespace bytesWaiting

09Empty input returns EOFWaiting

10Format whitespace consumes a full input run before %cWaiting

11Leading format whitespace skips input whitespaceWaiting

12Trailing format whitespace stops before the next non-space byteWaiting