Scanf optional input
I'm working on a project and I can't seem to figure out a way how to read a string with an int that's not always there. Then I'd like to put "string" in instruction and leave argument equal to 0.
But the program expects a number after "string" and won't continue until it gets it. How can I read input from stdin when I can have 2 different types of input? I tried several solutions, but none of them worked. By posting your answer, you agree to the privacy policy and terms of service. Stack Overflow Questions Developer Jobs Documentation beta Tags Users. Sign up or log in to customize your list.
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Stack Overflow is a community of 7. Join them; it only takes a minute: C - scanf string with optional int Ask Question. You do that by not trying to parse standard input directly.
scanf, _scanf_l, wscanf, _wscanf_l
Instead you Read a line of input with fgets. Attempt to parse that line into an integer possibly with sscanf: If you succeed you have your integer.
Otherwise you have the original string. Hi, could you elaborate a bit more how to attempt to parse with 'sscanf'? But bear in mind that scanf and sscanf function family all return a value: If not enough items, scanf will stall but sscanf will not.
WeatherVane Thank you, I absolutely did not realize that the functions returned a value.
scanf - C++ Reference
I tried to quickly throw something together and it seems to be working so far. Sign up or log in StackExchange.
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scanf format string - Wikipedia
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