Since your terminal is line buffered, your program doesn't see it yet, and so remains paused. You see the prompt and press a key (say, X).Since the stream is currently empty, it pauses your program until some input arrives. Your program calls getchar(), which tries to read a character from the standard input stream.The actual sequence of events looks like this: When you do press Enter, your program will receive any characters that you've typed, including the newline character ( \n) produced by the Enter key. This happens because your terminal is line buffered, so it's waiting for you to press Enter before passing any of the characters you've typed to your program. The leading space in the format string tells scanf to ignore any leading whitespace, so you won't pick up the newline character. } while ( a = '\n' ) // or while( isspace( a )), if you want to rejectĪnother is to not use getchar instead, use scanf with the %c conversion specifier and a blank space in the format string: scanf( " %c", &c ) // you will need to change the types of your One is to test your input, and try again if it's a newline: do There are a couple of ways to deal with this.
You can probably figure out what happens from here - the next getchar call reads that newline character from the input stream. In response to the second prompt, you type b c Enter, so your input stream now contains '\n', 'b', 'c', '\n'. The first getchar call reads the a and leaves the newline in the input stream. On the first prompt, you type something like a Enter, so your input stream contains the characters 'a', '\n'. The 3rd getchar() is a newline and that is expected.Ĭan anyone explain why when both segments are run in the same main(), the behavior is different from when run seperate? When they are run individually, the output is below.
Here is the output when both run together. If you comment out the entire first segment block, then it behaves correctly, picking up the first letter by the first getchar() and the second letter by the second getchar(), displaying the output as expected. The 3rd getchar() picks up the second letter. When you type the requested 2 letters, the first getchar() picks up a new line and the second getchar() picks up the first letter. In the second segment block, I added a 3rd variable to test my theory. * OR - outputs the same, to demonstrate putchar */ I have tried several IDE thinking it might be a bug. When both of these segment blocks are run in a main(), the second block does not behave as if it exists alone in the main(). This is training syntax, so don't ask me why it's done the way it is. It's hard to explain so I'll post the code. This is a long sentence to test the text wrap in a pragraph.I am taking a training course on "C" and running into a problem. \usepackage)īut linefeed and carriage return are recognized.Īnd long lines are just long lines: Test: This is a long sentence to test the text wrap in a pragraph. What is better depend of what you want, because the tree environments have several significant differences, as you can compare in this example: Said that, in addition to obeylines environment, another options are parse lines and verbatim environments. (I am thinking in lists, boxes with text, etc.) and no much more.) since probably there are better ways to obtain what you want without any \\. \linebreak and \par (See also Downsides of using \par instead of two new lines ) and then just use blank lines to make new paragraphs (not to make new lines) and as less as possible the line breaking commands (in the end of rows of tables. What is the difference between \newline and \\?, I now that in the it is boring at first, but my suggestion anyway is learn Wihouth figuring that you are trying to do exactly is hard to say, but except form small chunks of text is just a bad idea make that the end of line (EOL) equivalent to \\ or \newline.
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