xref: /onnv-gate/usr/src/lib/libcmd/common/fold.c (revision 12068:08a39a083754)
14887Schin /***********************************************************************
24887Schin *                                                                      *
34887Schin *               This software is part of the ast package               *
4*12068SRoger.Faulkner@Oracle.COM *          Copyright (c) 1992-2010 AT&T Intellectual Property          *
54887Schin *                      and is licensed under the                       *
64887Schin *                  Common Public License, Version 1.0                  *
78462SApril.Chin@Sun.COM *                    by AT&T Intellectual Property                     *
84887Schin *                                                                      *
94887Schin *                A copy of the License is available at                 *
104887Schin *            http://www.opensource.org/licenses/cpl1.0.txt             *
114887Schin *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
124887Schin *                                                                      *
134887Schin *              Information and Software Systems Research               *
144887Schin *                            AT&T Research                             *
154887Schin *                           Florham Park NJ                            *
164887Schin *                                                                      *
174887Schin *                 Glenn Fowler <gsf@research.att.com>                  *
184887Schin *                  David Korn <dgk@research.att.com>                   *
194887Schin *                                                                      *
204887Schin ***********************************************************************/
214887Schin #pragma prototyped
224887Schin /*
234887Schin  * David Korn
244887Schin  * AT&T Bell Laboratories
254887Schin  *
264887Schin  * fold
274887Schin  */
284887Schin 
294887Schin static const char usage[] =
304887Schin "[-?\n@(#)$Id: fold (AT&T Research) 2004-11-18 $\n]"
314887Schin USAGE_LICENSE
324887Schin "[+NAME?fold - fold lines]"
334887Schin "[+DESCRIPTION?\bfold\b is a filter that folds lines from its input, "
344887Schin 	"breaking the lines to have a maximum of \awidth\a column "
354887Schin 	"positions (or bytes if the \b-b\b option is specified).  Lines "
364887Schin 	"are broken by the insertion of a newline character such that "
374887Schin 	"each output line is the maximum width possible that does not "
384887Schin 	"exceed the specified number of column positions, (or bytes).  A line "
394887Schin 	"will not be broken in the middle of a character.] "
404887Schin "[+?Unless the \b-b\b option is specified, the following will be treated "
414887Schin 	"specially:]{"
424887Schin 	"[+carriage-return?The current count of line width will be set "
434887Schin 		"to zero.  \bfold\b will not insert a newline immediately "
444887Schin 		"before or after a carriage-return.]"
454887Schin 	"[+backspace?If positive, the current count of line width will be "
464887Schin 		"decremented by  one.  \bfold\b will not insert a newline "
474887Schin 		"immediately before or after a backspace.]"
484887Schin 	"[+tab?Each tab character encountered will advance the column "
494887Schin 		"position to the next tab stop.  Tab stops are at each "
504887Schin 		"column position \an\a, where \an\a modulo 8 equals 1.]"
514887Schin 	"}"
524887Schin "[+?If no \afile\a is given, or if the \afile\a is \b-\b, \bfold\b "
534887Schin         "reads from standard input.   The start of the file is defined "
544887Schin         "as the current offset.]"
554887Schin 
564887Schin "[b:bytes?Count bytes rather than columns so that each carriage-return, "
574887Schin 	"backspace, and tab counts as 1.]"
584887Schin "[c:continue?Emit \atext\a at line splits.]:[text:='\\n']"
594887Schin "[d:delimiter?Break at \adelim\a boundaries.]:[delim]"
604887Schin "[s:spaces?Break at word boundaries.  If the line contains any blanks, "
614887Schin 	"(spaces or tabs), within the first \awidth\a column positions or "
624887Schin 	"bytes, the line is broken after the last blank meeting the "
634887Schin 	"\awidth\a constraint.]"
644887Schin "[w:width]#[width:=80?Use a maximum line length of \awidth\a columns "
654887Schin 	"instead of the default.]"
664887Schin "\n"
674887Schin "\n[file ...]\n"
684887Schin "\n"
694887Schin "[+EXIT STATUS?]{"
704887Schin 	"[+0?All files processed successfully.]"
714887Schin 	"[+>0?An error occurred.]"
724887Schin "}"
734887Schin "[+SEE ALSO?\bpaste\b(1)]"
744887Schin ;
754887Schin 
764887Schin 
774887Schin #include <cmd.h>
784887Schin 
794887Schin #define WIDTH	80
804887Schin #define TABSIZE	8
814887Schin 
824887Schin #define T_EOF	1
834887Schin #define T_NL	2
844887Schin #define T_BS	3
854887Schin #define T_TAB	4
864887Schin #define T_SP	5
874887Schin #define T_RET	6
884887Schin 
fold(Sfio_t * in,Sfio_t * out,register int width,const char * cont,size_t contsize,char * cols)894887Schin static void fold(Sfio_t *in, Sfio_t *out, register int width, const char *cont, size_t contsize, char *cols)
904887Schin {
914887Schin 	register char *cp, *first;
924887Schin 	register int n, col=0, x=0;
934887Schin 	register char *last_space=0;
944887Schin 	cols[0] = 0;
954887Schin 	for (;;)
964887Schin 	{
974887Schin 		if (!(cp  = sfgetr(in,'\n',0)))
984887Schin 		{
994887Schin 			if (!(cp = sfgetr(in,'\n',-1)) || (n = sfvalue(in)) <= 0)
1004887Schin 				break;
1014887Schin 			x = cp[--n];
1024887Schin 			cp[n] = '\n';
1034887Schin 		}
1044887Schin 		/* special case -b since no column adjustment is needed */
1054887Schin 		if(cols['\b']==0 && (n=sfvalue(in))<=width)
1064887Schin 		{
1074887Schin 			sfwrite(out,cp,n);
1084887Schin 			continue;
1094887Schin 		}
1104887Schin 		first = cp;
1114887Schin 		col = 0;
1124887Schin 		last_space = 0;
1134887Schin 		for(;;)
1144887Schin 		{
1154887Schin 			while((n=cols[*(unsigned char*)cp++])==0);
1164887Schin 			while((cp-first) > (width-col))
1174887Schin 			{
1184887Schin 				if(last_space)
1194887Schin 					col = last_space - first;
1204887Schin 				else
1214887Schin 					col = width-col;
1224887Schin 				sfwrite(out,first,col);
1234887Schin 				first += col;
1244887Schin 				col = 0;
1254887Schin 				last_space = 0;
1264887Schin 				if(cp>first+1 || (n!=T_NL && n!=T_BS))
1274887Schin 					sfwrite(out, cont, contsize);
1284887Schin 			}
1294887Schin 			switch(n)
1304887Schin 			{
1314887Schin 			    case T_NL:
1324887Schin 				if(x)
1334887Schin 					*(cp-1) = x;
1344887Schin 				break;
1354887Schin 			    case T_RET:
1364887Schin 				col = 0;
1374887Schin 				continue;
1384887Schin 			    case T_BS:
1394887Schin 				if((cp+(--col)-first)>0)
1404887Schin 					col--;
1414887Schin 				continue;
1424887Schin 			    case T_TAB:
1434887Schin 				n = (TABSIZE-1) - (cp+col-1-first)&(TABSIZE-1);
1444887Schin 				col +=n;
1454887Schin 				if((cp-first) > (width-col))
1464887Schin 				{
1474887Schin 					sfwrite(out,first,(--cp)-first);
1484887Schin 					sfwrite(out, cont, contsize);
1494887Schin 					first = cp;
1504887Schin 					col =  TABSIZE-1;
1514887Schin 					last_space = 0;
1524887Schin 					continue;
1534887Schin 				}
1544887Schin 				if(cols[' '])
1554887Schin 					last_space = cp;
1564887Schin 				continue;
1574887Schin 			    case T_SP:
1584887Schin 				last_space = cp;
1594887Schin 				continue;
1604887Schin 			    default:
1614887Schin 				continue;
1624887Schin 			}
1634887Schin 			break;
1644887Schin 		}
1654887Schin 		sfwrite(out,first,cp-first);
1664887Schin 	}
1674887Schin }
1684887Schin 
1694887Schin int
b_fold(int argc,char * argv[],void * context)1704887Schin b_fold(int argc, char *argv[], void* context)
1714887Schin {
1724887Schin 	register int n, width=WIDTH;
1734887Schin 	register Sfio_t *fp;
1744887Schin 	register char *cp;
1754887Schin 	char *cont="\n";
1764887Schin 	size_t contsize = 1;
1774887Schin 	char cols[1<<CHAR_BIT];
1784887Schin 
1794887Schin 	cmdinit(argc, argv, context, ERROR_CATALOG, 0);
1804887Schin 	memset(cols, 0, sizeof(cols));
1814887Schin 	cols['\t'] = T_TAB;
1824887Schin 	cols['\b'] = T_BS;
1834887Schin 	cols['\n'] = T_NL;
1844887Schin 	cols['\r'] = T_RET;
1854887Schin 	for (;;)
1864887Schin 	{
1874887Schin 		switch (optget(argv, usage))
1884887Schin 		{
1894887Schin 		case 0:
1904887Schin 			break;
1914887Schin 		case 'b':
1924887Schin 			cols['\r'] = cols['\b'] = 0;
1934887Schin 			cols['\t'] = cols[' '];
1944887Schin 			continue;
1954887Schin 		case 'c':
1964887Schin 			contsize = stresc(cont = strdup(opt_info.arg));
1974887Schin 			continue;
1984887Schin 		case 'd':
1994887Schin 			if (n = *opt_info.arg)
2004887Schin 				cols[n] = T_SP;
2014887Schin 			continue;
2024887Schin 		case 's':
2034887Schin 			cols[' '] = T_SP;
2044887Schin 			if(cols['\t']==0)
2054887Schin 				cols['\t'] = T_SP;
2064887Schin 			continue;
2074887Schin 		case 'w':
2084887Schin 			if ((width = opt_info.num) <= 0)
2094887Schin 				error(2, "%d: width must be positive", opt_info.num);
2104887Schin 			continue;
2114887Schin 		case ':':
2124887Schin 			error(2, "%s", opt_info.arg);
2134887Schin 			continue;
2144887Schin 		case '?':
2154887Schin 			error(ERROR_usage(2), "%s", opt_info.arg);
2164887Schin 			continue;
2174887Schin 		}
2184887Schin 		break;
2194887Schin 	}
2204887Schin 	argv += opt_info.index;
2214887Schin 	argc -= opt_info.index;
2224887Schin 	if(error_info.errors)
2234887Schin 		error(ERROR_usage(2),"%s", optusage(NiL));
2244887Schin 	if(cp = *argv)
2254887Schin 		argv++;
2264887Schin 	do
2274887Schin 	{
2284887Schin 		if(!cp || streq(cp,"-"))
2294887Schin 			fp = sfstdin;
2304887Schin 		else if(!(fp = sfopen(NiL,cp,"r")))
2314887Schin 		{
2324887Schin 			error(ERROR_system(0),"%s: cannot open",cp);
2334887Schin 			error_info.errors = 1;
2344887Schin 			continue;
2354887Schin 		}
2364887Schin 		fold(fp,sfstdout,width,cont,contsize,cols);
2374887Schin 		if(fp!=sfstdin)
2384887Schin 			sfclose(fp);
2394887Schin 	}
2404887Schin 	while(cp= *argv++);
2414887Schin 	return(error_info.errors);
2424887Schin }
243