gets() is an unsafe method. Alternatives?

When executing a simple program I created through tutorials I am working through I am told by my OS that using gets is unsafe.

Is there an alternative to it that will allow strings to be entered, besides scanf() which seems to only accept a predefined number of variables.

gets(input); allows me to accept unlimited input regardless of whitespace

scanf("%s", input); only allows me to capture one word of the input.

I don't imagine it's wise to ignore OS warnings of this type, so if someone can tell me a better "safe" way to do this, please do.

Read the FAQ. Or just use fgets.


Quzah.

fgets is what I need. Having checked the FAQ it seems my answer is there.

Thanks.

For confirmation from the FAQ, please tell me if I am doing this correctly now:

Code:

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char input[81];

fgets(input, sizeof(input), stdin);

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Will doing this discard any input past 80 characters or is the if() statement in the example mandatory?

It wont discard it. It will sit waiting in the input buffer for the next read from stdin.

Quote:

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Originally Posted by ModeSix

When executing a simple program I created through tutorials I am working through I am told by my OS that using gets is unsafe.

Is there an alternative to it that will allow strings to be entered, besides scanf() which seems to only accept a predefined number of variables.

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using scanf without width modifier is also "unsafe"

when reading strings with scanf always add width modifier to prevent buffer overrun

Code:

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char buf[80];
scanf("%79s",buf);

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%s is not the only format for reading strings
%[^\n] will read input till \n is encountered

Quote:

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Originally Posted by anduril462

It wont discard it. It will sit waiting in the input buffer for the next read from stdin.

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Thank you. Is there a way to discard any overflow?

Quote:

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Originally Posted by vart

%[^\n] will read input until \n is encountered

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Will this also work with a width modifier? ex: %80[^\n] ?

Quote:

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Originally Posted by ModeSix

Thank you. Is there a way to discard any overflow?

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Read the FAQ - how to flush input buffer

Quote:

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Originally Posted by ModeSix

Will this also work with a width modifier? ex: %80[^\n] ?

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yes
Note that width should be 1 less than buffer size to have space for null terminator