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indent.c revision 1.14
      1 /*	$NetBSD: indent.c,v 1.14 2003/06/19 15:45:22 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1980, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  * Copyright (c) 1976 Board of Trustees of the University of Illinois.
      7  * Copyright (c) 1985 Sun Microsystems, Inc.
      8  * All rights reserved.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 #ifndef lint
     41 __COPYRIGHT("@(#) Copyright (c) 1985 Sun Microsystems, Inc.\n\
     42 @(#) Copyright (c) 1976 Board of Trustees of the University of Illinois.\n\
     43 @(#) Copyright (c) 1980, 1993\n\
     44 	The Regents of the University of California.  All rights reserved.\n");
     45 #endif				/* not lint */
     46 
     47 #ifndef lint
     48 #if 0
     49 static char sccsid[] = "@(#)indent.c	5.17 (Berkeley) 6/7/93";
     50 #else
     51 __RCSID("$NetBSD: indent.c,v 1.14 2003/06/19 15:45:22 christos Exp $");
     52 #endif
     53 #endif				/* not lint */
     54 
     55 #include <sys/param.h>
     56 #include <ctype.h>
     57 #include <err.h>
     58 #include <errno.h>
     59 #include <fcntl.h>
     60 #include <stdio.h>
     61 #include <stdlib.h>
     62 #include <string.h>
     63 #include <unistd.h>
     64 #include <locale.h>
     65 #define EXTERN
     66 #include "indent_globs.h"
     67 #undef  EXTERN
     68 #include "indent_codes.h"
     69 
     70 char   *in_name = "Standard Input";	/* will always point to name of input
     71 					 * file */
     72 char   *out_name = "Standard Output";	/* will always point to name of output
     73 					 * file */
     74 char    bakfile[MAXPATHLEN] = "";
     75 
     76 int main(int, char **);
     77 
     78 int
     79 main(int argc, char **argv)
     80 {
     81 
     82 	extern int found_err;	/* flag set in diag() on error */
     83 	int     dec_ind;	/* current indentation for declarations */
     84 	int     di_stack[20];	/* a stack of structure indentation levels */
     85 	int     flushed_nl;	/* used when buffering up comments to remember
     86 				 * that a newline was passed over */
     87 	int     force_nl;	/* when true, code must be broken */
     88 	int     hd_type;	/* used to store type of stmt for if (...),
     89 				 * for (...), etc */
     90 	int     i;		/* local loop counter */
     91 	int     scase;		/* set to true when we see a case, so we will
     92 				 * know what to do with the following colon */
     93 	int     sp_sw;		/* when true, we are in the expressin of
     94 				 * if(...), while(...), etc. */
     95 	int     squest;		/* when this is positive, we have seen a ?
     96 				 * without the matching : in a <c>?<s>:<s>
     97 				 * construct */
     98 	char   *t_ptr;		/* used for copying tokens */
     99 	int     type_code;	/* the type of token, returned by lexi */
    100 
    101 	int     last_else = 0;	/* true iff last keyword was an else */
    102 
    103 
    104 	/*-----------------------------------------------*\
    105         |		      INITIALIZATION		      |
    106         \*-----------------------------------------------*/
    107 
    108 	if (!setlocale(LC_ALL, ""))
    109 		fprintf(stderr, "indent: can't set locale.\n");
    110 
    111 	hd_type = 0;
    112 	ps.p_stack[0] = stmt;	/* this is the parser's stack */
    113 	ps.last_nl = true;	/* this is true if the last thing scanned was
    114 				 * a newline */
    115 	ps.last_token = semicolon;
    116 	combuf = (char *) malloc(bufsize);
    117 	labbuf = (char *) malloc(bufsize);
    118 	codebuf = (char *) malloc(bufsize);
    119 	tokenbuf = (char *) malloc(bufsize);
    120 	l_com = combuf + bufsize - 5;
    121 	l_lab = labbuf + bufsize - 5;
    122 	l_code = codebuf + bufsize - 5;
    123 	l_token = tokenbuf + bufsize - 5;
    124 	combuf[0] = codebuf[0] = labbuf[0] = ' ';	/* set up code, label,
    125 							 * and comment buffers */
    126 	combuf[1] = codebuf[1] = labbuf[1] = '\0';
    127 	ps.else_if = 1;		/* Default else-if special processing to on */
    128 	s_lab = e_lab = labbuf + 1;
    129 	s_code = e_code = codebuf + 1;
    130 	s_com = e_com = combuf + 1;
    131 	s_token = e_token = tokenbuf + 1;
    132 
    133 	in_buffer = (char *) malloc(10);
    134 	in_buffer_limit = in_buffer + 8;
    135 	buf_ptr = buf_end = in_buffer;
    136 	line_no = 1;
    137 	had_eof = ps.in_decl = ps.decl_on_line = break_comma = false;
    138 	sp_sw = force_nl = false;
    139 	ps.in_or_st = false;
    140 	ps.bl_line = true;
    141 	dec_ind = 0;
    142 	di_stack[ps.dec_nest = 0] = 0;
    143 	ps.want_blank = ps.in_stmt = ps.ind_stmt = false;
    144 
    145 
    146 	scase = ps.pcase = false;
    147 	squest = 0;
    148 	sc_end = 0;
    149 	bp_save = 0;
    150 	be_save = 0;
    151 
    152 	output = 0;
    153 
    154 
    155 
    156 	/*--------------------------------------------------*\
    157         |   		COMMAND LINE SCAN		 |
    158         \*--------------------------------------------------*/
    159 
    160 #ifdef undef
    161 	max_col = 78;		/* -l78 */
    162 	lineup_to_parens = 1;	/* -lp */
    163 	ps.ljust_decl = 0;	/* -ndj */
    164 	ps.com_ind = 33;	/* -c33 */
    165 	star_comment_cont = 1;	/* -sc */
    166 	ps.ind_size = 8;	/* -i8 */
    167 	verbose = 0;
    168 	ps.decl_indent = 16;	/* -di16 */
    169 	ps.indent_parameters = 1;	/* -ip */
    170 	ps.decl_com_ind = 0;	/* if this is not set to some positive value
    171 				 * by an arg, we will set this equal to
    172 				 * ps.com_ind */
    173 	btype_2 = 1;		/* -br */
    174 	cuddle_else = 1;	/* -ce */
    175 	ps.unindent_displace = 0;	/* -d0 */
    176 	ps.case_indent = 0;	/* -cli0 */
    177 	format_col1_comments = 1;	/* -fc1 */
    178 	procnames_start_line = 1;	/* -psl */
    179 	proc_calls_space = 0;	/* -npcs */
    180 	comment_delimiter_on_blankline = 1;	/* -cdb */
    181 	ps.leave_comma = 1;	/* -nbc */
    182 #endif
    183 
    184 	for (i = 1; i < argc; ++i)
    185 		if (strcmp(argv[i], "-npro") == 0)
    186 			break;
    187 	set_defaults();
    188 	if (i >= argc)
    189 		set_profile();
    190 
    191 	for (i = 1; i < argc; ++i) {
    192 
    193 		/*
    194 		 * look thru args (if any) for changes to defaults
    195 		 */
    196 		if (argv[i][0] != '-') {	/* no flag on parameter */
    197 			if (input == 0) {	/* we must have the input file */
    198 				in_name = argv[i];	/* remember name of
    199 							 * input file */
    200 				input = fopen(in_name, "r");
    201 				if (input == 0)	/* check for open error */
    202 					err(1, "%s", in_name);
    203 				continue;
    204 			} else
    205 				if (output == 0) {	/* we have the output
    206 							 * file */
    207 					out_name = argv[i];	/* remember name of
    208 								 * output file */
    209 					if (strcmp(in_name, out_name) == 0) {	/* attempt to overwrite
    210 										 * the file */
    211 						fprintf(stderr, "indent: input and output files must be different\n");
    212 						exit(1);
    213 					}
    214 					output = fopen(out_name, "w");
    215 					if (output == 0)	/* check for create
    216 								 * error */
    217 						err(1, "%s", out_name);
    218 					continue;
    219 				}
    220 			fprintf(stderr, "indent: unknown parameter: %s\n", argv[i]);
    221 			exit(1);
    222 		} else
    223 			set_option(argv[i]);
    224 	}			/* end of for */
    225 	if (input == 0) {
    226 		input = stdin;
    227 	}
    228 	if (output == 0) {
    229 		if (troff || input == stdin)
    230 			output = stdout;
    231 		else {
    232 			out_name = in_name;
    233 			bakcopy();
    234 		}
    235 	}
    236 	if (ps.com_ind <= 1)
    237 		ps.com_ind = 2;	/* dont put normal comments before column 2 */
    238 	if (troff) {
    239 		if (bodyf.font[0] == 0)
    240 			parsefont(&bodyf, "R");
    241 		if (scomf.font[0] == 0)
    242 			parsefont(&scomf, "I");
    243 		if (blkcomf.font[0] == 0)
    244 			blkcomf = scomf, blkcomf.size += 2;
    245 		if (boxcomf.font[0] == 0)
    246 			boxcomf = blkcomf;
    247 		if (stringf.font[0] == 0)
    248 			parsefont(&stringf, "L");
    249 		if (keywordf.font[0] == 0)
    250 			parsefont(&keywordf, "B");
    251 		writefdef(&bodyf, 'B');
    252 		writefdef(&scomf, 'C');
    253 		writefdef(&blkcomf, 'L');
    254 		writefdef(&boxcomf, 'X');
    255 		writefdef(&stringf, 'S');
    256 		writefdef(&keywordf, 'K');
    257 	}
    258 	if (block_comment_max_col <= 0)
    259 		block_comment_max_col = max_col;
    260 	if (ps.decl_com_ind <= 0)	/* if not specified by user, set this */
    261 		ps.decl_com_ind = ps.ljust_decl ? (ps.com_ind <= 10 ? 2 : ps.com_ind - 8) : ps.com_ind;
    262 	if (continuation_indent == 0)
    263 		continuation_indent = ps.ind_size;
    264 	fill_buffer();		/* get first batch of stuff into input buffer */
    265 
    266 	parse(semicolon);
    267 	{
    268 		char   *p = buf_ptr;
    269 		int     col = 1;
    270 
    271 		while (1) {
    272 			if (*p == ' ')
    273 				col++;
    274 			else
    275 				if (*p == '\t')
    276 					col = ((col - 1) & ~7) + 9;
    277 				else
    278 					break;
    279 			p++;
    280 		}
    281 		if (col > ps.ind_size)
    282 			ps.ind_level = ps.i_l_follow = col / ps.ind_size;
    283 	}
    284 	if (troff) {
    285 		char   *p = in_name, *beg = in_name;
    286 
    287 		while (*p)
    288 			if (*p++ == '/')
    289 				beg = p;
    290 		fprintf(output, ".Fn \"%s\"\n", beg);
    291 	}
    292 	/*
    293          * START OF MAIN LOOP
    294          */
    295 
    296 	while (1) {		/* this is the main loop.  it will go until we
    297 				 * reach eof */
    298 		int     is_procname;
    299 
    300 		type_code = lexi();	/* lexi reads one token.  The actual
    301 					 * characters read are stored in
    302 					 * "token". lexi returns a code
    303 					 * indicating the type of token */
    304 		is_procname = ps.procname[0];
    305 
    306 		/*
    307 		 * The following code moves everything following an if (), while (),
    308 		 * else, etc. up to the start of the following stmt to a buffer. This
    309 		 * allows proper handling of both kinds of brace placement.
    310 		 */
    311 
    312 		flushed_nl = false;
    313 		while (ps.search_brace) {	/* if we scanned an if(),
    314 						 * while(), etc., we might
    315 						 * need to copy stuff into a
    316 						 * buffer we must loop,
    317 						 * copying stuff into
    318 						 * save_com, until we find the
    319 						 * start of the stmt which
    320 						 * follows the if, or whatever */
    321 			switch (type_code) {
    322 			case newline:
    323 				++line_no;
    324 				flushed_nl = true;
    325 			case form_feed:
    326 				break;	/* form feeds and newlines found here
    327 					 * will be ignored */
    328 
    329 			case lbrace:	/* this is a brace that starts the
    330 					 * compound stmt */
    331 				if (sc_end == 0) {	/* ignore buffering if a
    332 							 * comment wasnt stored
    333 							 * up */
    334 					ps.search_brace = false;
    335 					goto check_type;
    336 				}
    337 				if (btype_2) {
    338 					save_com[0] = '{';	/* we either want to put
    339 								 * the brace right after
    340 								 * the if */
    341 					goto sw_buffer;	/* go to common code to
    342 							 * get out of this loop */
    343 				}
    344 			case comment:	/* we have a comment, so we must copy
    345 					 * it into the buffer */
    346 				if (!flushed_nl || sc_end != 0) {
    347 					if (sc_end == 0) {	/* if this is the first
    348 								 * comment, we must set
    349 								 * up the buffer */
    350 						save_com[0] = save_com[1] = ' ';
    351 						sc_end = &(save_com[2]);
    352 					} else {
    353 						*sc_end++ = '\n';	/* add newline between
    354 									 * comments */
    355 						*sc_end++ = ' ';
    356 						--line_no;
    357 					}
    358 					*sc_end++ = '/';	/* copy in start of
    359 								 * comment */
    360 					*sc_end++ = '*';
    361 
    362 					for (;;) {	/* loop until we get to
    363 							 * the end of the
    364 							 * comment */
    365 						*sc_end = *buf_ptr++;
    366 						if (buf_ptr >= buf_end)
    367 							fill_buffer();
    368 
    369 						if (*sc_end++ == '*' && *buf_ptr == '/')
    370 							break;	/* we are at end of
    371 								 * comment */
    372 
    373 						if (sc_end >= &(save_com[sc_size])) {	/* check for temp buffer
    374 											 * overflow */
    375 							diag(1, "Internal buffer overflow - Move big comment from right after if, while, or whatever.");
    376 							fflush(output);
    377 							exit(1);
    378 						}
    379 					}
    380 					*sc_end++ = '/';	/* add ending slash */
    381 					if (++buf_ptr >= buf_end)	/* get past / in buffer */
    382 						fill_buffer();
    383 					break;
    384 				}
    385 			default:	/* it is the start of a normal
    386 					 * statment */
    387 				if (flushed_nl)	/* if we flushed a newline,
    388 						 * make sure it is put back */
    389 					force_nl = true;
    390 				if ((type_code == sp_paren && *token == 'i'
    391 					&& last_else && ps.else_if) ||
    392 				    (type_code == sp_nparen && *token == 'e'
    393 					&& e_code != s_code && e_code[-1] == '}'))
    394 					force_nl = false;
    395 
    396 				if (sc_end == 0) {	/* ignore buffering if
    397 							 * comment wasnt saved
    398 							 * up */
    399 					ps.search_brace = false;
    400 					goto check_type;
    401 				}
    402 				if (force_nl) {	/* if we should insert a nl
    403 						 * here, put it into the
    404 						 * buffer */
    405 					force_nl = false;
    406 					--line_no;	/* this will be
    407 							 * re-increased when the
    408 							 * nl is read from the
    409 							 * buffer */
    410 					*sc_end++ = '\n';
    411 					*sc_end++ = ' ';
    412 					if (verbose && !flushed_nl)	/* print error msg if
    413 									 * the line was not
    414 									 * already broken */
    415 						diag(0, "Line broken");
    416 					flushed_nl = false;
    417 				}
    418 				for (t_ptr = token; *t_ptr; ++t_ptr)
    419 					*sc_end++ = *t_ptr;	/* copy token into temp
    420 								 * buffer */
    421 				ps.procname[0] = 0;
    422 
    423 		sw_buffer:
    424 				ps.search_brace = false;	/* stop looking for
    425 								 * start of stmt */
    426 				bp_save = buf_ptr;	/* save current input
    427 							 * buffer */
    428 				be_save = buf_end;
    429 				buf_ptr = save_com;	/* fix so that
    430 							 * subsequent calls to
    431 							 * lexi will take tokens
    432 							 * out of save_com */
    433 				*sc_end++ = ' ';	/* add trailing blank,
    434 							 * just in case */
    435 				buf_end = sc_end;
    436 				sc_end = 0;
    437 				break;
    438 			}	/* end of switch */
    439 			if (type_code != 0)	/* we must make this check,
    440 						 * just in case there was an
    441 						 * unexpected EOF */
    442 				type_code = lexi();	/* read another token */
    443 			/* if (ps.search_brace) ps.procname[0] = 0; */
    444 			if ((is_procname = ps.procname[0]) && flushed_nl
    445 			    && !procnames_start_line && ps.in_decl
    446 			    && type_code == ident)
    447 				flushed_nl = 0;
    448 		}		/* end of while (search_brace) */
    449 		last_else = 0;
    450 check_type:
    451 		if (type_code == 0) {	/* we got eof */
    452 			if (s_lab != e_lab || s_code != e_code
    453 			    || s_com != e_com)	/* must dump end of line */
    454 				dump_line();
    455 			if (ps.tos > 1)	/* check for balanced braces */
    456 				diag(1, "Stuff missing from end of file.");
    457 
    458 			if (verbose) {
    459 				printf("There were %d output lines and %d comments\n",
    460 				    ps.out_lines, ps.out_coms);
    461 				printf("(Lines with comments)/(Lines with code): %6.3f\n",
    462 				    (1.0 * ps.com_lines) / code_lines);
    463 			}
    464 			fflush(output);
    465 			exit(found_err);
    466 		}
    467 		if (
    468 		    (type_code != comment) &&
    469 		    (type_code != newline) &&
    470 		    (type_code != preesc) &&
    471 		    (type_code != form_feed)) {
    472 			if (force_nl &&
    473 			    (type_code != semicolon) &&
    474 			    (type_code != lbrace || !btype_2)) {
    475 				/* we should force a broken line here */
    476 				if (verbose && !flushed_nl)
    477 					diag(0, "Line broken");
    478 				flushed_nl = false;
    479 				dump_line();
    480 				ps.want_blank = false;	/* dont insert blank at
    481 							 * line start */
    482 				force_nl = false;
    483 			}
    484 			ps.in_stmt = true;	/* turn on flag which causes
    485 						 * an extra level of
    486 						 * indentation. this is turned
    487 						 * off by a ; or '}' */
    488 			if (s_com != e_com) {	/* the turkey has embedded a
    489 						 * comment in a line. fix it */
    490 				*e_code++ = ' ';
    491 				for (t_ptr = s_com; *t_ptr; ++t_ptr) {
    492 					CHECK_SIZE_CODE;
    493 					*e_code++ = *t_ptr;
    494 				}
    495 				*e_code++ = ' ';
    496 				*e_code = '\0';	/* null terminate code sect */
    497 				ps.want_blank = false;
    498 				e_com = s_com;
    499 			}
    500 		} else
    501 			if (type_code != comment)	/* preserve force_nl
    502 							 * thru a comment */
    503 				force_nl = false;	/* cancel forced newline
    504 							 * after newline, form
    505 							 * feed, etc */
    506 
    507 
    508 
    509 		/*-----------------------------------------------------*\
    510 		|	   do switch on type of token scanned		|
    511 		\*-----------------------------------------------------*/
    512 		CHECK_SIZE_CODE;
    513 		switch (type_code) {	/* now, decide what to do with the
    514 					 * token */
    515 
    516 		case form_feed:/* found a form feed in line */
    517 			ps.use_ff = true;	/* a form feed is treated much
    518 						 * like a newline */
    519 			dump_line();
    520 			ps.want_blank = false;
    521 			break;
    522 
    523 		case newline:
    524 			if (ps.last_token != comma || ps.p_l_follow > 0
    525 			    || !ps.leave_comma || ps.block_init || !break_comma || s_com != e_com) {
    526 				dump_line();
    527 				ps.want_blank = false;
    528 			}
    529 			++line_no;	/* keep track of input line number */
    530 			break;
    531 
    532 		case lparen:	/* got a '(' or '[' */
    533 			++ps.p_l_follow;	/* count parens to make Healy
    534 						 * happy */
    535 			if (ps.want_blank && *token != '[' &&
    536 			    (ps.last_token != ident || proc_calls_space
    537 				|| (ps.its_a_keyword && (!ps.sizeof_keyword || Bill_Shannon))))
    538 				*e_code++ = ' ';
    539 			if (ps.in_decl && !ps.block_init) {
    540 				if (troff && !ps.dumped_decl_indent && !is_procname && ps.last_token == decl) {
    541 					ps.dumped_decl_indent = 1;
    542 					sprintf(e_code, "\n.Du %dp+\200p \"%s\"\n", dec_ind * 7, token);
    543 					e_code += strlen(e_code);
    544 				} else {
    545 					while ((e_code - s_code) < dec_ind) {
    546 						CHECK_SIZE_CODE;
    547 						*e_code++ = ' ';
    548 					}
    549 					*e_code++ = token[0];
    550 				}
    551 			} else
    552 				*e_code++ = token[0];
    553 			ps.paren_indents[ps.p_l_follow - 1] = e_code - s_code;
    554 			if (sp_sw && ps.p_l_follow == 1 && extra_expression_indent
    555 			    && ps.paren_indents[0] < 2 * ps.ind_size)
    556 				ps.paren_indents[0] = 2 * ps.ind_size;
    557 			ps.want_blank = false;
    558 			if (ps.in_or_st && *token == '(' && ps.tos <= 2) {
    559 				/*
    560 				 * this is a kluge to make sure that declarations will be
    561 				 * aligned right if proc decl has an explicit type on it, i.e.
    562 				 * "int a(x) {..."
    563 				 */
    564 				parse(semicolon);	/* I said this was a
    565 							 * kluge... */
    566 				ps.in_or_st = false;	/* turn off flag for
    567 							 * structure decl or
    568 							 * initialization */
    569 			}
    570 			if (ps.sizeof_keyword)
    571 				ps.sizeof_mask |= 1 << ps.p_l_follow;
    572 			break;
    573 
    574 		case rparen:	/* got a ')' or ']' */
    575 			rparen_count--;
    576 			if (ps.cast_mask & (1 << ps.p_l_follow) & ~ps.sizeof_mask) {
    577 				ps.last_u_d = true;
    578 				ps.cast_mask &= (1 << ps.p_l_follow) - 1;
    579 			}
    580 			ps.sizeof_mask &= (1 << ps.p_l_follow) - 1;
    581 			if (--ps.p_l_follow < 0) {
    582 				ps.p_l_follow = 0;
    583 				diag(0, "Extra %c", *token);
    584 			}
    585 			if (e_code == s_code)	/* if the paren starts the
    586 						 * line */
    587 				ps.paren_level = ps.p_l_follow;	/* then indent it */
    588 
    589 			*e_code++ = token[0];
    590 			ps.want_blank = true;
    591 
    592 			if (sp_sw && (ps.p_l_follow == 0)) {	/* check for end of if
    593 								 * (...), or some such */
    594 				sp_sw = false;
    595 				force_nl = true;	/* must force newline
    596 							 * after if */
    597 				ps.last_u_d = true;	/* inform lexi that a
    598 							 * following operator is
    599 							 * unary */
    600 				ps.in_stmt = false;	/* dont use stmt
    601 							 * continuation
    602 							 * indentation */
    603 
    604 				parse(hd_type);	/* let parser worry about if,
    605 						 * or whatever */
    606 			}
    607 			ps.search_brace = btype_2;	/* this should insure
    608 							 * that constructs such
    609 							 * as main(){...} and
    610 							 * int[]{...} have their
    611 							 * braces put in the
    612 							 * right place */
    613 			break;
    614 
    615 		case unary_op:	/* this could be any unary operation */
    616 			if (ps.want_blank)
    617 				*e_code++ = ' ';
    618 
    619 			if (troff && !ps.dumped_decl_indent && ps.in_decl && !is_procname) {
    620 				sprintf(e_code, "\n.Du %dp+\200p \"%s\"\n", dec_ind * 7, token);
    621 				ps.dumped_decl_indent = 1;
    622 				e_code += strlen(e_code);
    623 			} else {
    624 				char   *res = token;
    625 
    626 				if (ps.in_decl && !ps.block_init) {	/* if this is a unary op
    627 									 * in a declaration, we
    628 									 * should indent this
    629 									 * token */
    630 					for (i = 0; token[i]; ++i);	/* find length of token */
    631 					while ((e_code - s_code) < (dec_ind - i)) {
    632 						CHECK_SIZE_CODE;
    633 						*e_code++ = ' ';	/* pad it */
    634 					}
    635 				}
    636 				if (troff && token[0] == '-' && token[1] == '>')
    637 					res = "\\(->";
    638 				for (t_ptr = res; *t_ptr; ++t_ptr) {
    639 					CHECK_SIZE_CODE;
    640 					*e_code++ = *t_ptr;
    641 				}
    642 			}
    643 			ps.want_blank = false;
    644 			break;
    645 
    646 		case binary_op:/* any binary operation */
    647 			if (ps.want_blank)
    648 				*e_code++ = ' ';
    649 			{
    650 				char   *res = token;
    651 
    652 				if (troff)
    653 					switch (token[0]) {
    654 					case '<':
    655 						if (token[1] == '=')
    656 							res = "\\(<=";
    657 						break;
    658 					case '>':
    659 						if (token[1] == '=')
    660 							res = "\\(>=";
    661 						break;
    662 					case '!':
    663 						if (token[1] == '=')
    664 							res = "\\(!=";
    665 						break;
    666 					case '|':
    667 						if (token[1] == '|')
    668 							res = "\\(br\\(br";
    669 						else
    670 							if (token[1] == 0)
    671 								res = "\\(br";
    672 						break;
    673 					}
    674 				for (t_ptr = res; *t_ptr; ++t_ptr) {
    675 					CHECK_SIZE_CODE;
    676 					*e_code++ = *t_ptr;	/* move the operator */
    677 				}
    678 			}
    679 			ps.want_blank = true;
    680 			break;
    681 
    682 		case postop:	/* got a trailing ++ or -- */
    683 			*e_code++ = token[0];
    684 			*e_code++ = token[1];
    685 			ps.want_blank = true;
    686 			break;
    687 
    688 		case question:	/* got a ? */
    689 			squest++;	/* this will be used when a later
    690 					 * colon appears so we can distinguish
    691 					 * the <c>?<n>:<n> construct */
    692 			if (ps.want_blank)
    693 				*e_code++ = ' ';
    694 			*e_code++ = '?';
    695 			ps.want_blank = true;
    696 			break;
    697 
    698 		case casestmt:	/* got word 'case' or 'default' */
    699 			scase = true;	/* so we can process the later colon
    700 					 * properly */
    701 			goto copy_id;
    702 
    703 		case colon:	/* got a ':' */
    704 			if (squest > 0) {	/* it is part of the <c>?<n>:
    705 						 * <n> construct */
    706 				--squest;
    707 				if (ps.want_blank)
    708 					*e_code++ = ' ';
    709 				*e_code++ = ':';
    710 				ps.want_blank = true;
    711 				break;
    712 			}
    713 			if (ps.in_or_st) {
    714 				*e_code++ = ':';
    715 				ps.want_blank = false;
    716 				break;
    717 			}
    718 			ps.in_stmt = false;	/* seeing a label does not
    719 						 * imply we are in a stmt */
    720 			for (t_ptr = s_code; *t_ptr; ++t_ptr)
    721 				*e_lab++ = *t_ptr;	/* turn everything so
    722 							 * far into a label */
    723 			e_code = s_code;
    724 			*e_lab++ = ':';
    725 			*e_lab++ = ' ';
    726 			*e_lab = '\0';
    727 
    728 			force_nl = ps.pcase = scase;	/* ps.pcase will be used
    729 							 * by dump_line to
    730 							 * decide how to indent
    731 							 * the label. force_nl
    732 							 * will force a case n:
    733 							 * to be on a line by
    734 							 * itself */
    735 			scase = false;
    736 			ps.want_blank = false;
    737 			break;
    738 
    739 		case semicolon:/* got a ';' */
    740 			ps.in_or_st = false;	/* we are not in an
    741 						 * initialization or structure
    742 						 * declaration */
    743 			scase = false;	/* these will only need resetting in a
    744 					 * error */
    745 			squest = 0;
    746 			if (ps.last_token == rparen && rparen_count == 0)
    747 				ps.in_parameter_declaration = 0;
    748 			ps.cast_mask = 0;
    749 			ps.sizeof_mask = 0;
    750 			ps.block_init = 0;
    751 			ps.block_init_level = 0;
    752 			ps.just_saw_decl--;
    753 
    754 			if (ps.in_decl && s_code == e_code && !ps.block_init)
    755 				while ((e_code - s_code) < (dec_ind - 1)) {
    756 					CHECK_SIZE_CODE;
    757 					*e_code++ = ' ';
    758 				}
    759 
    760 			ps.in_decl = (ps.dec_nest > 0);	/* if we were in a first
    761 							 * level structure
    762 							 * declaration, we arent
    763 							 * any more */
    764 
    765 			if ((!sp_sw || hd_type != forstmt) && ps.p_l_follow > 0) {
    766 
    767 				/*
    768 				 * This should be true iff there were unbalanced parens in the
    769 				 * stmt.  It is a bit complicated, because the semicolon might
    770 				 * be in a for stmt
    771 				 */
    772 				diag(1, "Unbalanced parens");
    773 				ps.p_l_follow = 0;
    774 				if (sp_sw) {	/* this is a check for a if,
    775 						 * while, etc. with unbalanced
    776 						 * parens */
    777 					sp_sw = false;
    778 					parse(hd_type);	/* dont lose the if, or
    779 							 * whatever */
    780 				}
    781 			}
    782 			*e_code++ = ';';
    783 			ps.want_blank = true;
    784 			ps.in_stmt = (ps.p_l_follow > 0);	/* we are no longer in
    785 								 * the middle of a stmt */
    786 
    787 			if (!sp_sw) {	/* if not if for (;;) */
    788 				parse(semicolon);	/* let parser know about
    789 							 * end of stmt */
    790 				force_nl = true;	/* force newline after a
    791 							 * end of stmt */
    792 			}
    793 			break;
    794 
    795 		case lbrace:	/* got a '{' */
    796 			ps.in_stmt = false;	/* dont indent the {} */
    797 			if (!ps.block_init)
    798 				force_nl = true;	/* force other stuff on
    799 							 * same line as '{' onto
    800 							 * new line */
    801 			else
    802 				if (ps.block_init_level <= 0)
    803 					ps.block_init_level = 1;
    804 				else
    805 					ps.block_init_level++;
    806 
    807 			if (s_code != e_code && !ps.block_init) {
    808 				if (!btype_2) {
    809 					dump_line();
    810 					ps.want_blank = false;
    811 				} else
    812 					if (ps.in_parameter_declaration && !ps.in_or_st) {
    813 						ps.i_l_follow = 0;
    814 						dump_line();
    815 						ps.want_blank = false;
    816 					}
    817 			}
    818 			if (ps.in_parameter_declaration)
    819 				prefix_blankline_requested = 0;
    820 
    821 			if (ps.p_l_follow > 0) {	/* check for preceding
    822 							 * unbalanced parens */
    823 				diag(1, "Unbalanced parens");
    824 				ps.p_l_follow = 0;
    825 				if (sp_sw) {	/* check for unclosed if, for,
    826 						 * etc. */
    827 					sp_sw = false;
    828 					parse(hd_type);
    829 					ps.ind_level = ps.i_l_follow;
    830 				}
    831 			}
    832 			if (s_code == e_code)
    833 				ps.ind_stmt = false;	/* dont put extra
    834 							 * indentation on line
    835 							 * with '{' */
    836 			if (ps.in_decl && ps.in_or_st) {	/* this is either a
    837 								 * structure declaration
    838 								 * or an init */
    839 				di_stack[ps.dec_nest++] = dec_ind;
    840 				/* ?		dec_ind = 0; */
    841 			} else {
    842 				ps.decl_on_line = false;	/* we cant be in the
    843 								 * middle of a
    844 								 * declaration, so dont
    845 								 * do special
    846 								 * indentation of
    847 								 * comments */
    848 				if (blanklines_after_declarations_at_proctop
    849 				    && ps.in_parameter_declaration)
    850 					postfix_blankline_requested = 1;
    851 				ps.in_parameter_declaration = 0;
    852 			}
    853 			dec_ind = 0;
    854 			parse(lbrace);	/* let parser know about this */
    855 			if (ps.want_blank)	/* put a blank before '{' if
    856 						 * '{' is not at start of line */
    857 				*e_code++ = ' ';
    858 			ps.want_blank = false;
    859 			*e_code++ = '{';
    860 			ps.just_saw_decl = 0;
    861 			break;
    862 
    863 		case rbrace:	/* got a '}' */
    864 			if (ps.p_stack[ps.tos] == decl && !ps.block_init)	/* semicolons can be
    865 										 * omitted in
    866 										 * declarations */
    867 				parse(semicolon);
    868 			if (ps.p_l_follow) {	/* check for unclosed if, for,
    869 						 * else. */
    870 				diag(1, "Unbalanced parens");
    871 				ps.p_l_follow = 0;
    872 				sp_sw = false;
    873 			}
    874 			ps.just_saw_decl = 0;
    875 			ps.block_init_level--;
    876 			if (s_code != e_code && !ps.block_init) {	/* '}' must be first on
    877 									 * line */
    878 				if (verbose)
    879 					diag(0, "Line broken");
    880 				dump_line();
    881 			}
    882 			*e_code++ = '}';
    883 			ps.want_blank = true;
    884 			ps.in_stmt = ps.ind_stmt = false;
    885 			if (ps.dec_nest > 0) {	/* we are in multi-level
    886 						 * structure declaration */
    887 				dec_ind = di_stack[--ps.dec_nest];
    888 				if (ps.dec_nest == 0 && !ps.in_parameter_declaration)
    889 					ps.just_saw_decl = 2;
    890 				ps.in_decl = true;
    891 			}
    892 			prefix_blankline_requested = 0;
    893 			parse(rbrace);	/* let parser know about this */
    894 			ps.search_brace = cuddle_else && ps.p_stack[ps.tos] == ifhead
    895 			    && ps.il[ps.tos] >= ps.ind_level;
    896 			if (ps.tos <= 1 && blanklines_after_procs && ps.dec_nest <= 0)
    897 				postfix_blankline_requested = 1;
    898 			break;
    899 
    900 		case swstmt:	/* got keyword "switch" */
    901 			sp_sw = true;
    902 			hd_type = swstmt;	/* keep this for when we have
    903 						 * seen the expression */
    904 			goto copy_id;	/* go move the token into buffer */
    905 
    906 		case sp_paren:	/* token is if, while, for */
    907 			sp_sw = true;	/* the interesting stuff is done after
    908 					 * the expression is scanned */
    909 			hd_type = (*token == 'i' ? ifstmt :
    910 			    (*token == 'w' ? whilestmt : forstmt));
    911 
    912 			/*
    913 		         * remember the type of header for later use by parser
    914 		         */
    915 			goto copy_id;	/* copy the token into line */
    916 
    917 		case sp_nparen:/* got else, do */
    918 			ps.in_stmt = false;
    919 			if (*token == 'e') {
    920 				if (e_code != s_code && (!cuddle_else || e_code[-1] != '}')) {
    921 					if (verbose)
    922 						diag(0, "Line broken");
    923 					dump_line();	/* make sure this starts
    924 							 * a line */
    925 					ps.want_blank = false;
    926 				}
    927 				force_nl = true;	/* also, following stuff
    928 							 * must go onto new line */
    929 				last_else = 1;
    930 				parse(elselit);
    931 			} else {
    932 				if (e_code != s_code) {	/* make sure this starts
    933 							 * a line */
    934 					if (verbose)
    935 						diag(0, "Line broken");
    936 					dump_line();
    937 					ps.want_blank = false;
    938 				}
    939 				force_nl = true;	/* also, following stuff
    940 							 * must go onto new line */
    941 				last_else = 0;
    942 				parse(dolit);
    943 			}
    944 			goto copy_id;	/* move the token into line */
    945 
    946 		case decl:	/* we have a declaration type (int, register,
    947 				 * etc.) */
    948 			parse(decl);	/* let parser worry about indentation */
    949 			if (ps.last_token == rparen && ps.tos <= 1) {
    950 				ps.in_parameter_declaration = 1;
    951 				if (s_code != e_code) {
    952 					dump_line();
    953 					ps.want_blank = 0;
    954 				}
    955 			}
    956 			if (ps.in_parameter_declaration && ps.indent_parameters && ps.dec_nest == 0) {
    957 				ps.ind_level = ps.i_l_follow = 1;
    958 				ps.ind_stmt = 0;
    959 			}
    960 			ps.in_or_st = true;	/* this might be a structure
    961 						 * or initialization
    962 						 * declaration */
    963 			ps.in_decl = ps.decl_on_line = true;
    964 			if ( /* !ps.in_or_st && */ ps.dec_nest <= 0)
    965 				ps.just_saw_decl = 2;
    966 			prefix_blankline_requested = 0;
    967 			for (i = 0; token[i++];);	/* get length of token */
    968 
    969 			/*
    970 		         * dec_ind = e_code - s_code + (ps.decl_indent>i ? ps.decl_indent
    971 		         * : i);
    972 		         */
    973 			dec_ind = ps.decl_indent > 0 ? ps.decl_indent : i;
    974 			goto copy_id;
    975 
    976 		case ident:	/* got an identifier or constant */
    977 			if (ps.in_decl) {	/* if we are in a declaration,
    978 						 * we must indent identifier */
    979 				if (ps.want_blank)
    980 					*e_code++ = ' ';
    981 				ps.want_blank = false;
    982 				if (is_procname == 0 || !procnames_start_line) {
    983 					if (!ps.block_init) {
    984 						if (troff && !ps.dumped_decl_indent) {
    985 							sprintf(e_code, "\n.De %dp+\200p\n", dec_ind * 7);
    986 							ps.dumped_decl_indent = 1;
    987 							e_code += strlen(e_code);
    988 						} else
    989 							while ((e_code - s_code) < dec_ind) {
    990 								CHECK_SIZE_CODE;
    991 								*e_code++ = ' ';
    992 							}
    993 					}
    994 				} else {
    995 					if (dec_ind && s_code != e_code)
    996 						dump_line();
    997 					dec_ind = 0;
    998 					ps.want_blank = false;
    999 				}
   1000 			} else
   1001 				if (sp_sw && ps.p_l_follow == 0) {
   1002 					sp_sw = false;
   1003 					force_nl = true;
   1004 					ps.last_u_d = true;
   1005 					ps.in_stmt = false;
   1006 					parse(hd_type);
   1007 				}
   1008 	copy_id:
   1009 			if (ps.want_blank)
   1010 				*e_code++ = ' ';
   1011 			if (troff && ps.its_a_keyword) {
   1012 				e_code = chfont(&bodyf, &keywordf, e_code);
   1013 				for (t_ptr = token; *t_ptr; ++t_ptr) {
   1014 					CHECK_SIZE_CODE;
   1015 					*e_code++ = keywordf.allcaps && islower((unsigned char)*t_ptr)
   1016 					    ? toupper(*t_ptr) : *t_ptr;
   1017 				}
   1018 				e_code = chfont(&keywordf, &bodyf, e_code);
   1019 			} else
   1020 				for (t_ptr = token; *t_ptr; ++t_ptr) {
   1021 					CHECK_SIZE_CODE;
   1022 					*e_code++ = *t_ptr;
   1023 				}
   1024 			ps.want_blank = true;
   1025 			break;
   1026 
   1027 		case period:	/* treat a period kind of like a binary
   1028 				 * operation */
   1029 			*e_code++ = '.';	/* move the period into line */
   1030 			ps.want_blank = false;	/* dont put a blank after a
   1031 						 * period */
   1032 			break;
   1033 
   1034 		case comma:
   1035 			ps.want_blank = (s_code != e_code);	/* only put blank after
   1036 								 * comma if comma does
   1037 								 * not start the line */
   1038 			if (ps.in_decl && is_procname == 0 && !ps.block_init)
   1039 				while ((e_code - s_code) < (dec_ind - 1)) {
   1040 					CHECK_SIZE_CODE;
   1041 					*e_code++ = ' ';
   1042 				}
   1043 
   1044 			*e_code++ = ',';
   1045 			if (ps.p_l_follow == 0) {
   1046 				if (ps.block_init_level <= 0)
   1047 					ps.block_init = 0;
   1048 				if (break_comma && (!ps.leave_comma || compute_code_target() + (e_code - s_code) > max_col - 8))
   1049 					force_nl = true;
   1050 			}
   1051 			break;
   1052 
   1053 		case preesc:	/* got the character '#' */
   1054 			if ((s_com != e_com) ||
   1055 			    (s_lab != e_lab) ||
   1056 			    (s_code != e_code))
   1057 				dump_line();
   1058 			*e_lab++ = '#';	/* move whole line to 'label' buffer */
   1059 			{
   1060 				int     in_comment = 0;
   1061 				int     com_start = 0;
   1062 				char    quote = 0;
   1063 				int     com_end = 0;
   1064 
   1065 				while (*buf_ptr == ' ' || *buf_ptr == '\t') {
   1066 					buf_ptr++;
   1067 					if (buf_ptr >= buf_end)
   1068 						fill_buffer();
   1069 				}
   1070 				while (*buf_ptr != '\n' || in_comment) {
   1071 					CHECK_SIZE_LAB;
   1072 					*e_lab = *buf_ptr++;
   1073 					if (buf_ptr >= buf_end)
   1074 						fill_buffer();
   1075 					switch (*e_lab++) {
   1076 					case BACKSLASH:
   1077 						if (troff)
   1078 							*e_lab++ = BACKSLASH;
   1079 						if (!in_comment) {
   1080 							*e_lab++ = *buf_ptr++;
   1081 							if (buf_ptr >= buf_end)
   1082 								fill_buffer();
   1083 						}
   1084 						break;
   1085 					case '/':
   1086 						if (*buf_ptr == '*' && !in_comment && !quote) {
   1087 							in_comment = 1;
   1088 							*e_lab++ = *buf_ptr++;
   1089 							com_start = e_lab - s_lab - 2;
   1090 						}
   1091 						break;
   1092 					case '"':
   1093 						if (quote == '"')
   1094 							quote = 0;
   1095 						break;
   1096 					case '\'':
   1097 						if (quote == '\'')
   1098 							quote = 0;
   1099 						break;
   1100 					case '*':
   1101 						if (*buf_ptr == '/' && in_comment) {
   1102 							in_comment = 0;
   1103 							*e_lab++ = *buf_ptr++;
   1104 							com_end = e_lab - s_lab;
   1105 						}
   1106 						break;
   1107 					}
   1108 				}
   1109 
   1110 				while (e_lab > s_lab && (e_lab[-1] == ' ' || e_lab[-1] == '\t'))
   1111 					e_lab--;
   1112 				if (e_lab - s_lab == com_end && bp_save == 0) {	/* comment on
   1113 										 * preprocessor line */
   1114 					if (sc_end == 0)	/* if this is the first
   1115 								 * comment, we must set
   1116 								 * up the buffer */
   1117 						sc_end = &(save_com[0]);
   1118 					else {
   1119 						*sc_end++ = '\n';	/* add newline between
   1120 									 * comments */
   1121 						*sc_end++ = ' ';
   1122 						--line_no;
   1123 					}
   1124 					memmove(sc_end, s_lab + com_start, com_end - com_start);
   1125 					sc_end += com_end - com_start;
   1126 					if (sc_end >= &save_com[sc_size])
   1127 						abort();
   1128 					e_lab = s_lab + com_start;
   1129 					while (e_lab > s_lab && (e_lab[-1] == ' ' || e_lab[-1] == '\t'))
   1130 						e_lab--;
   1131 					bp_save = buf_ptr;	/* save current input
   1132 								 * buffer */
   1133 					be_save = buf_end;
   1134 					buf_ptr = save_com;	/* fix so that
   1135 								 * subsequent calls to
   1136 								 * lexi will take tokens
   1137 								 * out of save_com */
   1138 					*sc_end++ = ' ';	/* add trailing blank,
   1139 								 * just in case */
   1140 					buf_end = sc_end;
   1141 					sc_end = 0;
   1142 				}
   1143 				*e_lab = '\0';	/* null terminate line */
   1144 				ps.pcase = false;
   1145 			}
   1146 
   1147 			if (strncmp(s_lab, "#if", 3) == 0) {
   1148 				if (blanklines_around_conditional_compilation) {
   1149 					int     c;
   1150 					prefix_blankline_requested++;
   1151 					while ((c = getc(input)) == '\n');
   1152 					ungetc(c, input);
   1153 				}
   1154 				if (ifdef_level < sizeof state_stack / sizeof state_stack[0]) {
   1155 					match_state[ifdef_level].tos = -1;
   1156 					state_stack[ifdef_level++] = ps;
   1157 				} else
   1158 					diag(1, "#if stack overflow");
   1159 			} else
   1160 				if (strncmp(s_lab, "#else", 5) == 0) {
   1161 					if (ifdef_level <= 0)
   1162 						diag(1, "Unmatched #else");
   1163 					else {
   1164 						match_state[ifdef_level - 1] = ps;
   1165 						ps = state_stack[ifdef_level - 1];
   1166 					}
   1167 				} else
   1168 					if (strncmp(s_lab, "#endif", 6) == 0) {
   1169 						if (ifdef_level <= 0)
   1170 							diag(1, "Unmatched #endif");
   1171 						else {
   1172 							ifdef_level--;
   1173 
   1174 #ifdef undef
   1175 							/*
   1176 						         * This match needs to be more intelligent before the
   1177 						         * message is useful
   1178 						         */
   1179 							if (match_state[ifdef_level].tos >= 0
   1180 							    && memcmp(&ps, &match_state[ifdef_level], sizeof ps))
   1181 								diag(0, "Syntactically inconsistant #ifdef alternatives.");
   1182 #endif
   1183 						}
   1184 						if (blanklines_around_conditional_compilation) {
   1185 							postfix_blankline_requested++;
   1186 							n_real_blanklines = 0;
   1187 						}
   1188 					}
   1189 			break;	/* subsequent processing of the newline
   1190 				 * character will cause the line to be printed */
   1191 
   1192 		case comment:	/* we have gotten a start comment */
   1193 			/* this is a biggie */
   1194 			if (flushed_nl) {	/* we should force a broken
   1195 						 * line here */
   1196 				flushed_nl = false;
   1197 				dump_line();
   1198 				ps.want_blank = false;	/* dont insert blank at
   1199 							 * line start */
   1200 				force_nl = false;
   1201 			}
   1202 			pr_comment();
   1203 			break;
   1204 		}		/* end of big switch stmt */
   1205 
   1206 		*e_code = '\0';	/* make sure code section is null terminated */
   1207 		if (type_code != comment && type_code != newline && type_code != preesc)
   1208 			ps.last_token = type_code;
   1209 	}			/* end of main while (1) loop */
   1210 }
   1211 /*
   1212  * copy input file to backup file if in_name is /blah/blah/blah/file, then
   1213  * backup file will be ".Bfile" then make the backup file the input and
   1214  * original input file the output
   1215  */
   1216 void
   1217 bakcopy(void)
   1218 {
   1219 	int     n, bakchn;
   1220 	char    buff[8 * 1024];
   1221 	char   *p;
   1222 
   1223 	/* construct file name .Bfile */
   1224 	for (p = in_name; *p; p++);	/* skip to end of string */
   1225 	while (p > in_name && *p != '/')	/* find last '/' */
   1226 		p--;
   1227 	if (*p == '/')
   1228 		p++;
   1229 	sprintf(bakfile, "%s.BAK", p);
   1230 
   1231 	/* copy in_name to backup file */
   1232 	bakchn = creat(bakfile, 0600);
   1233 	if (bakchn < 0)
   1234 		err(1, "%s", bakfile);
   1235 	while ((n = read(fileno(input), buff, sizeof buff)) > 0)
   1236 		if (write(bakchn, buff, n) != n)
   1237 			err(1, "%s", bakfile);
   1238 	if (n < 0)
   1239 		err(1, "%s", in_name);
   1240 	close(bakchn);
   1241 	fclose(input);
   1242 
   1243 	/* re-open backup file as the input file */
   1244 	input = fopen(bakfile, "r");
   1245 	if (input == 0)
   1246 		err(1, "%s", bakfile);
   1247 	/* now the original input file will be the output */
   1248 	output = fopen(in_name, "w");
   1249 	if (output == 0) {
   1250 		unlink(bakfile);
   1251 		err(1, "%s", in_name);
   1252 	}
   1253 }
   1254