How can I get a string from input without including a newline using fgets? [duplicate]

问题

I'm trying to write an inputted string elsewhere and do not know how to do away with the new line that appears as part of this string that I acquire with stdin and fgets.

 char buffer[100];
 memset(buffer, 0, 100);
 fgets(buffer, 100, stdin);
 printf("buffer is: %s\n stop",buffer);

I tried to limit the amount of data that fgets gets as well as limiting how much of the data is written but the new line remains. How can I simply get the inputted string up to the last character written with nothing else?

回答1:

try

fgets(buffer, 100, stdin);
size_t ln = strlen(buffer)-1;
if (buffer[ln] == '\n')
    buffer[ln] = '\0';

回答2:

Simply look for the potential '\n'.

After calling fgets(), If '\n' exists, it will be the last char in the string (just before the '\0').

size_t len = strlen(buffer);
if (len > 0 && buffer[len-1] == '\n') {
  buffer[--len] = '\0';
}

Sample usage

char buffer[100];
// memset(buffer, 0, 100); not needed
if (fgets(buffer, sizeof buffer, stdin) == NULL) { // good to test fgets() result
  Handle_EOForIOerror();
}
size_t len = strlen(buffer);
if (len > 0 && buffer[len-1] == '\n') {
  buffer[--len] = '\0';
}
printf("buffer is: %s\n stop",buffer);

Notes:

buffer[strlen(buffer)-1] is dangerous in rare occasions when the first char in buffer is a '\0' (embedded null character).

scanf("%99[^\n]%*c", buffer); is a problem if the first char is '\n', nothing is read and '\n' remains in stdin.

strlen() is fast as compared to other methods: https://codereview.stackexchange.com/a/67756/29485

Or roll your own code like gets_sz

来源：https://stackoverflow.com/questions/27491005/how-can-i-get-a-string-from-input-without-including-a-newline-using-fgets

标签

newline

stdin

fgets