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    <p>When you use <code>scanf()</code> to read the strings, your format string (<code>%[^\n]</code>) tells the function to read every character that is not <code>'\n'</code>. That leaves the <code>'\n'</code> character in the input buffer. So when you try to read <code>str2</code> and <code>str3</code>, <code>scanf()</code> finds the first thing in the buffer is <code>'\n'</code> each time and, because of the format string, doesn't remove it from the input buffer. What you need is a <code>getchar()</code> between the times that you read from the input buffer (often placed immediately after <code>scanf()</code>). Since there is already a <code>'\n'</code> in the buffer, your program won't appear to hang because it won't have to wait for input for <code>getchar()</code> to receive. Try it. :)</p> <p>For those who haven't a clue what that <code>scanf()</code> modifier does, here is a relevant excerpt from <a href="http://linux.die.net/man/3/scanf">http://linux.die.net/man/3/scanf</a> -</p> <blockquote> <p>[</p> <p>Matches a nonempty sequence of characters from the specified set of accepted characters; the next pointer must be a pointer to char, and there must be enough room for all the characters in the string, plus a terminating null byte. The usual skip of leading white space is suppressed. The string is to be made up of characters in (or not in) a particular set; the set is defined by the characters between the open bracket [ character and a close bracket ] character. The set excludes those characters if the first character after the open bracket is a circumflex (^). To include a close bracket in the set, make it the first character after the open bracket or the circumflex; any other position will end the set. The hyphen character - is also special; when placed between two other characters, it adds all intervening characters to the set. To include a hyphen, make it the last character before the final close bracket. For instance, [^]0-9-] means the set "everything except close bracket, zero through nine, and hyphen". The string ends with the appearance of a character not in the (or, with a circumflex, in) set or when the field width runs out.</p> </blockquote>
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    1. POscanf: "%[^\n]" skips the 2nd input but " %[^\n]" does not. why?
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    1. USChrono Kitsune
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    1. COsame question to you also: then what the trailing blank space signifies in " %[^\n]" . This will work correctly.
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    2. COWhen you add a leading space to the format string, it is evaluated as any character that the function `isspace()` would return a truthy value for, including `'\n'`, `' '`, `'\t'`, etc. This means that the space character before the next non-space character in the format string is ignored.
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    3. COIf you use a trailing space (a space at the end of the format string), your program appears to hang. Instead of entering a blank line or using space characters, you must enter what the value of str2 will be. The same for str3 and when it asks for str3's value, you would enter a value that won't appear. For example, use `"%[^\n] "` instead of `"%[^\n]"`/`" %[^\n]"`. Your newline will be ignored as specified...and eaten by the trailing space in the format string. Since scanf didn't get a '\n' character, it will want more data. str2 will have that value and str3 will have str2's value.
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