/**************************************************************************** * lib/stdio/lib_fgets.c * * Copyright (C) 2007-2008, 2011-2012 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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. Neither the name NuttX 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 COPYRIGHT HOLDERS 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 * COPYRIGHT OWNER 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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include /**************************************************************************** * Definitions ****************************************************************************/ /* Some environments may return CR as end-of-line, others LF, and others * both. If not specified, the logic here assumes either (but not both) as * the default. */ #if defined(CONFIG_EOL_IS_CR) # undef CONFIG_EOL_IS_LF # undef CONFIG_EOL_IS_BOTH_CRLF # undef CONFIG_EOL_IS_EITHER_CRLF #elif defined(CONFIG_EOL_IS_LF) # undef CONFIG_EOL_IS_CR # undef CONFIG_EOL_IS_BOTH_CRLF # undef CONFIG_EOL_IS_EITHER_CRLF #elif defined(CONFIG_EOL_IS_BOTH_CRLF) # undef CONFIG_EOL_IS_CR # undef CONFIG_EOL_IS_LF # undef CONFIG_EOL_IS_EITHER_CRLF #elif defined(CONFIG_EOL_IS_EITHER_CRLF) # undef CONFIG_EOL_IS_CR # undef CONFIG_EOL_IS_LF # undef CONFIG_EOL_IS_BOTH_CRLF #else # undef CONFIG_EOL_IS_CR # undef CONFIG_EOL_IS_LF # undef CONFIG_EOL_IS_BOTH_CRLF # define CONFIG_EOL_IS_EITHER_CRLF 1 #endif /**************************************************************************** * Private Type Declarations ****************************************************************************/ /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /**************************************************************************** * Public Data ****************************************************************************/ /**************************************************************************** * Private Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Global Functions ****************************************************************************/ /**************************************************************************** * Name: fgets * * Description: * fgets() reads in at most one less than 'buflen' characters from stream * and stores them into the buffer pointed to by 'buf'. Reading stops after * an EOF or a newline. If a newline is read, it is stored into the * buffer. A null terminator is stored after the last character in the * buffer. * **************************************************************************/ char *fgets(FAR char *buf, int buflen, FILE *stream) { int nch = 0; /* Sanity checks */ if (!stream || !buf || buflen < 1 || stream->fs_filedes < 0) { return NULL; } if (buflen < 2) { *buf = '\0'; return buf; } /* Read characters until we have a full line. On each the loop we must * be assured that there are two free bytes in the line buffer: One for * the next character and one for the null terminator. */ for(;;) { /* Get the next character */ int ch = fgetc(stream); /* Check for end-of-line. This is tricky only in that some * environments may return CR as end-of-line, others LF, and * others both. */ #if defined(CONFIG_EOL_IS_LF) || defined(CONFIG_EOL_IS_BOTH_CRLF) if (ch == '\n') #elif defined(CONFIG_EOL_IS_CR) if (ch == '\r') #elif CONFIG_EOL_IS_EITHER_CRLF if (ch == '\n' || ch == '\r') #endif { /* The newline is stored in the buffer along with the null * terminator. */ buf[nch++] = '\n'; buf[nch] = '\0'; return buf; } /* Check for end-of-file */ else if (ch == EOF) { /* End of file with no data? */ if (!nch) { /* Yes.. return NULL as the end of file mark */ return NULL; } else { /* Terminate the line */ buf[nch] = '\0'; return buf; } } /* Otherwise, check if the character is printable and, if so, put the * character in the line buffer */ else if (isprint(ch)) { buf[nch++] = ch; /* Check if there is room for another character and the line's * null terminator. If not then we have to end the line now. */ if (nch + 1 >= buflen) { buf[nch] = '\0'; return buf; } } } }