Author: gbe (doc committer) Date: Thu Jun 18 13:13:04 2020 New Revision: 362326 URL: https://svnweb.freebsd.org/changeset/base/362326
Log: fgetln(3): Add a Caveats Section Reviewed by: yuripv, bcr (mentor) Approved by: bcr (mentror) Obtained from: OpenBSD MFC after: 7 days Differential Revision: https://reviews.freebsd.org/D24916 Modified: head/lib/libc/stdio/fgetln.3 Modified: head/lib/libc/stdio/fgetln.3 ============================================================================== --- head/lib/libc/stdio/fgetln.3 Thu Jun 18 12:29:24 2020 (r362325) +++ head/lib/libc/stdio/fgetln.3 Thu Jun 18 13:13:04 2020 (r362326) @@ -28,7 +28,7 @@ .\" @(#)fgetln.3 8.3 (Berkeley) 4/19/94 .\" $FreeBSD$ .\" -.Dd February 15, 2016 +.Dd June 11, 2020 .Dt FGETLN 3 .Os .Sh NAME @@ -126,3 +126,33 @@ The .Fn fgetln function first appeared in .Bx 4.4 . +.Sh CAVEATS +Since the returned buffer is not a C string (it is not NUL terminated), a +common practice is to replace the newline character with +.Sq \e0 . +However, if the last line in a file does not contain a newline, +the returned text won't contain a newline either. +The following code demonstrates how to deal with this problem by allocating a +temporary buffer: +.Bd -literal + char *buf, *lbuf; + size_t len; + + lbuf = NULL; + while ((buf = fgetln(fp, &len)) != NULL) { + if (buf[len - 1] == '\en') + buf[len - 1] = '\e0'; + else { + /* EOF without EOL, copy and add the NUL */ + if ((lbuf = malloc(len + 1)) == NULL) + err(1, NULL); + memcpy(lbuf, buf, len); + lbuf[len] = '\e0'; + buf = lbuf; + } + printf("%s\en", buf); + } + free(lbuf); + if (ferror(fp)) + err(1, "fgetln"); +.Ed _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
