Active Oldest Votes. Improve this answer. Also, you're reinitting i i to 0 in every iteration of thewhile loop. H2CO3 Shouldn't this comment belong in the question's comments section? Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown.
The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually. The main drawback of scanf to use to input string; is that the function terminates as soon as it finds a blank space. Also note that, for scanning strings, you do not need the ampersand character precede the string name str. Null character gets automatically appended on encountering a blank space to mark the end of string.
Using gets function in C : Should no longer be used : Using gets , string can be read as follows: gets str ; gets overcomes the shortcomings of scanf. Gets stands for get string. The function takes starting address of the string which will hold the input and automatically appends the null character at the end of the string. This function is deprecated — that means it is obsolete and it is strongly suggested we do not use it — because it is dangerous.
It is dangerous because it provides no protection against buffer overflow; overflowing the string into which it is saving data. Since it is sometimes used in older code which is why the GNU C Library still provides it , we need to understand how it is used.
The gets function takes one parameter, the string in which to store the data which is read. It reads characters from standard input up to the next newline character that is, when the user presses Enter button , discards the newline character, and copies the rest of the data into the string.
If there was no error, it returns the same string ; otherwise, if there was an error, it returns a null pointer. We shall see going ahead our first string operation example using gets. Rather than reading a string from standard input, fgets reads it from a specified stream, usually file stream up to and including a newline character.
It stores the string in the string variable passed to it, adding a null character to terminate the string. This function takes three parameters: the first is the string into which to read data, the second is the maximum number of characters to read.
The third parameter is the stream from which to read. The number of characters that fgets reads is one less than than number specified; it stores the null character in the last character space. You must supply at least as many characters of space in the string, or your program might crash, but at least the fgets function protects against overflowing the string and creating a security hazard.
If there is no error, fgets returns the string read as a return value else for example if the stream is already at end of file, it returns a null pointer. Unfortunately, like the gets function, fgets is deprecated, in this case because when fgets cannot tell whether a null character is included in the string it reads. If a null character is read by fgets, it will be stored in the string along with the rest of the characters read.
Since a null character terminates a string in C, C will end your string prematurely, right before the first null character. Only use fgets if you are certain the data read cannot contain a null; otherwise, use getline. Using getline function in C: Preferred Method : The getline function is the preferred method for reading lines of text. The other functions like gets, fgets, and scanf, are unreliable for reasons already seen above and must be avoided.
The getline function reads an entire line from a stream, up to and including the next newline character. The first is a pointer to a block allocated with malloc or calloc which allocates memory for the program when run. The third parameter is simply the stream from where to read the line. The getline function automatically will enlarge the block of memory as needed, via realloc function, so there is never a shortage of space one reason why getline is safe. We will understand better in the below mentioned example.
It will also tell us the new size of the block by the value returned in the second parameter. If an error occurs, such as end of file etc.
Although the second parameter is of type pointer to string , you cannot treat it as an ordinary string, since it may contain null characters before the final null character marking the end of the line. The return value enables you to distinguish null characters that getline read as part of the line, by specifying the size of the line.
As we can see in the above program, it takes a single character at the run time from the user using the getchar function. After getting the character, it prints the letter through the putchar function. As we can see in the above output, a while loop continuously accepts a character from the user until the user does not pass the character.
Here the getchar function takes a single character from the standard input and assigns them to a ch variable. Whereas the putchar function prints the read character. As we can see, when we execute the above program, it takes a single character or group of characters using the scanf library function instead of the getchar function.
But there is a small difference; a scanf function can take a single or group of characters from the user, whereas the getchar function can only accept the single character. In the above program, a do-while loop continuously accepts the characters until the user passes the ENTER button to exit the loop. JavaTpoint offers too many high quality services. Mail us on [email protected] , to get more information about given services. Please mail your requirement at [email protected] Duration: 1 week to 2 week.
Command Line Arguments. Operator in C. Enter a character If we want to exit.. Enter the character Apple You have entered A. Enter the characters from the keyboard Press Enter button to stop. Well b47gvb come Entered characters are Well b47gvb come. Next Topic flowchart in C. Reinforcement Learning. R Programming. React Native.
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