NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c-part2/14320

Internet Message Format | 1996-08-05 | 2.0 KB

Path: mail2news.demon.co.uk!genesis.demon.co.uk
From: Lawrence Kirby <[e-mail]>
Newsgroups: comp.lang.c,comp.unix.programmer
Subject: Re: Q: '\n' character
Date: Sat, 13 Apr 96 11:54:33 GMT
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Message-ID: <[e-mail]>
References: <4kj66f$[e-mail]> <[e-mail]>
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In article <[e-mail]> [e-mail] "Mark Brader" writes:

>> > Is there a function or some sort of way that I could remove '\n'
>> > charecter form the end of the string.
>>
>> fgets(buffer, file);
>> buffer[strlen(buffer)-1]=0;
>>
>> It may not be the fastest, but it is darned near the easiest.
>
>Or the buggiest.  Instead use:
>
>  len = strlen (buffer);
>  if (len > 0 && buffer[len-1] == '\n') buffer[len-1] = '\0';
>
>Both tests in the "if" are necessary.

Not exactly true. fgets() can never place a zero length string in the
buffer. However its return value can be a null pointer on end-of-file or
failure and that condition must be tested for. fgets() will leave the buffer
unchanged if it encounters end-of-file but that is the only case where
you could legally test for and possibly find a zero length string. So the
code should look something like:

    if (fgets(buffer, file) != NULL) {
        size_t len = strlen(buffer);

        if (buffer[len-1] == '\n') buffer[len-1] = '\0';
    }

>In the specific case of a string obtained from fgets(), we can be
>sure that if there is a newline then it is the last character.
>This leads to the alternative approach:
>
>  ptr = strchr (buffer, '\n');   /* or strrchr() */
>  if (ptr) *ptr = '\0';

Or the very alternative approach:

      strtok(buffer, "\n");

But in both cases you still need to test the return code of fgets().

--
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Lawrence Kirby | [e-mail]
Wilts, England | [e-mail]
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