From: William F. Jolitz Date: Sat, 29 Jun 1991 21:26:08 +0000 (-0800) Subject: 386BSD 0.1 development X-Git-Tag: 386BSD-0.1~1245 X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/commitdiff_plain/1ed3a85eb1d601c6fb3fc25d286adfe42a050a33 386BSD 0.1 development Work on file usr/src/lib/libc/stdio/fgets.3 Co-Authored-By: Lynne Greer Jolitz Synthesized-from: 386BSD-0.1 --- diff --git a/usr/src/lib/libc/stdio/fgets.3 b/usr/src/lib/libc/stdio/fgets.3 new file mode 100644 index 0000000000..8676aee498 --- /dev/null +++ b/usr/src/lib/libc/stdio/fgets.3 @@ -0,0 +1,151 @@ +.\" Copyright (c) 1990, 1991 The Regents of the University of California. +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to Berkeley by +.\" Chris Torek and the American National Standards Committee X3, +.\" on Information Processing Systems. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)fgets.3 6.9 (Berkeley) 6/29/91 +.\" +.Dd June 29, 1991 +.Dt FGETS 3 +.Os +.Sh NAME +.Nm fgets , +.Nm gets +.Nd get a line from a stream +.Sh SYNOPSIS +.Fd #include +.Ft char * +.Fn fgets "char *str" "size_t size" "FILE *stream" +.Ft char * +.Fn gets "char *str" +.Sh DESCRIPTION +The +.Fn fgets +function +reads at most one less than the number of characters specified by +.Xr size +from the given +.Fa stream +and stores them in the string +.Fa str . +Reading stops when a newline character is found, +at end-of-file or error. +The newline, if any, is retained. +In any case a +.Ql \e0 +character is appended to end the string. +.Pp +The +.Fn gets +function +is equivalent to +.Fn fgets +with an infinite +.Xr size +and a +.Fa stream +of +.Em stdin , +except that the newline character (if any) is not stored in the string. +It is the caller's responsibility to ensure that the input line, +if any, is sufficiently short to fit in the string. +.Sh RETURN VALUES +.Pp +Upon successful completion, +.Fn fgets +and +.Fn gets +return +a pointer to the string. +If end-of-file or an error occurs before any characters are read, +they return +.Dv NULL. +The +.Fn fgets +and +functions +.Fn gets +do not distinguish between end-of-file and error, and callers must use +.Xr feof 3 +and +.Xr ferror 3 +to determine which occurred. +.Sh ERRORS +.Bl -tag -width [EBADF] +.It Bq Er EBADF +The given +.Fa stream +is not a readable stream. +.El +.Pp +The function +.Fn fgets +may also fail and set +.Va errno +for any of the errors specified for the routines +.Xr fflush 3 , +.Xr fstat 2 , +.Xr read 2 , +or +.Xr malloc 3 . +.Pp +The function +.Fn gets +may also fail and set +.Va errno +for any of the errors specified for the routine +.Xr getchar 3 . +.Sh SEE ALSO +.Xr feof 3 , +.Xr ferror 3 , +.Xr fgetline 3 +.Sh STANDARDS +The functions +.Fn fgets +and +.Fn gets +conform to +.St -ansiC . +.Sh BUGS +Since it is usually impossible to ensure that the next input line +is less than some arbitrary length, and because overflowing the +input buffer is almost invariably a security violation, programs +should +.Em NEVER +use +.Fn gets . +The +.Fn gets +function +exists purely to conform to +.St -ansiC .