Re: Can we use strings with scanf?
On Mon, Jan 25, 2021 at 06:43:18PM +, Rempas via Digitalmars-d-learn wrote: > On Monday, 25 January 2021 at 18:28:09 UTC, Ferhat Kurtulmuş wrote: > > On Monday, 25 January 2021 at 17:38:21 UTC, Rempas wrote: > > > On Monday, 25 January 2021 at 10:33:14 UTC, Mike Parker wrote: > > > > [...] > > > > > > Thanks! Actually for some reason. It won't accept a char[size]. I > > > created a heap allocated (with pureFree and pureMalloc) chrar*, > > > then used fgets() and created an empty string and looped through > > > the result adding one by one character until the '\n' which is not > > > included. > > > > char[buffsize] works if buffsize is a compile time constant. Or just > > char[1024]. İt is a static array, and it's size must be defined at > > compile time. > > Idk, for my it says that you can't pass dynamic arrays to scanf Dynamic arrays in D are "fat" pointers, they have a .ptr and .length, but scanf expects C-style bare pointers, so you have to specify .ptr in order to pass the pointer to scanf. Be aware, however, that doing this means you no longer have D's bounds-checking protection, and scanf may cause buffer overruns if the user gives bad input. T -- Being able to learn is a great learning; being able to unlearn is a greater learning.
Re: Can we use strings with scanf?
On Monday, 25 January 2021 at 18:28:09 UTC, Ferhat Kurtulmuş wrote: On Monday, 25 January 2021 at 17:38:21 UTC, Rempas wrote: On Monday, 25 January 2021 at 10:33:14 UTC, Mike Parker wrote: [...] Thanks! Actually for some reason. It won't accept a char[size]. I created a heap allocated (with pureFree and pureMalloc) chrar*, then used fgets() and created an empty string and looped through the result adding one by one character until the '\n' which is not included. char[buffsize] works if buffsize is a compile time constant. Or just char[1024]. İt is a static array, and it's size must be defined at compile time. Idk, for my it says that you can't pass dynamic arrays to scanf
Re: Can we use strings with scanf?
On Monday, 25 January 2021 at 17:38:21 UTC, Rempas wrote:
On Monday, 25 January 2021 at 10:33:14 UTC, Mike Parker wrote:
On Monday, 25 January 2021 at 09:16:11 UTC, Rempas wrote:
[...]
The * has a different meaning for scanf than for printf ([1]
vs [2]).
There's also the issue that a string is immutable(char)[].
If you really, really, really, must use scanf:
```
char[bufSize] buf;
scanf("%s", buf.ptr);
```
But please don't. This is D, not 1990s C.
[1] https://www.cplusplus.com/reference/cstdio/scanf/
[2] https://www.cplusplus.com/reference/cstdio/printf/
Thanks! Actually for some reason. It won't accept a char[size].
I created a heap allocated (with pureFree and pureMalloc)
chrar*, then used fgets() and created an empty string and
looped through the result adding one by one character until the
'\n' which is not included.
char[buffsize] works if buffsize is a compile time constant. Or
just char[1024]. İt is a static array, and it's size must be
defined at compile time.
Re: Can we use strings with scanf?
On Monday, 25 January 2021 at 10:33:14 UTC, Mike Parker wrote:
On Monday, 25 January 2021 at 09:16:11 UTC, Rempas wrote:
For printf() we can use this format `"%.*s", cast(int)s
s.length, s.ptr`. When trying to use the same for scanf(), it
says that this specifier is invalid.
The * has a different meaning for scanf than for printf ([1] vs
[2]).
There's also the issue that a string is immutable(char)[].
If you really, really, really, must use scanf:
```
char[bufSize] buf;
scanf("%s", buf.ptr);
```
But please don't. This is D, not 1990s C.
[1] https://www.cplusplus.com/reference/cstdio/scanf/
[2] https://www.cplusplus.com/reference/cstdio/printf/
Thanks! Actually for some reason. It won't accept a char[size]. I
created a heap allocated (with pureFree and pureMalloc) chrar*,
then used fgets() and created an empty string and looped through
the result adding one by one character until the '\n' which is
not included.
Re: Can we use strings with scanf?
On Monday, 25 January 2021 at 09:16:11 UTC, Rempas wrote:
For printf() we can use this format `"%.*s", cast(int)s
s.length, s.ptr`. When trying to use the same for scanf(), it
says that this specifier is invalid.
The * has a different meaning for scanf than for printf ([1] vs
[2]).
There's also the issue that a string is immutable(char)[].
If you really, really, really, must use scanf:
```
char[bufSize] buf;
scanf("%s", buf.ptr);
```
But please don't. This is D, not 1990s C.
[1] https://www.cplusplus.com/reference/cstdio/scanf/
[2] https://www.cplusplus.com/reference/cstdio/printf/
Can we use strings with scanf?
For printf() we can use this format `"%.*s", cast(int)s s.length, s.ptr`. When trying to use the same for scanf(), it says that this specifier is invalid.
