1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include <ctype.h>
5 
6 /*
7  * block up paragraphs, possibly with indentation
8  */
9 
10 int extraindent = 0;		/* how many spaces to indent all lines */
11 int indent = 0;			/* current value of indent, before extra indent */
12 int length = 70;		/* how many columns per output line */
13 int join = 1;			/* can lines be joined? */
14 int maxtab = 8;
15 Biobuf bin;
16 Biobuf bout;
17 
18 typedef struct Word Word;
19 struct Word{
20 	int	bol;
21 	int	indent;
22 	char	text[1];
23 };
24 
25 void	fmt(void);
26 
27 void
28 usage(void)
29 {
30 	fprint(2, "usage: %s [-j] [-i indent] [-l length] [file...]\n", argv0);
31 	exits("usage");
32 }
33 
34 void
35 main(int argc, char **argv)
36 {
37 	int i, f;
38 	char *s, *err;
39 
40 	ARGBEGIN{
41 	case 'i':
42 		extraindent = atoi(EARGF(usage()));
43 		break;
44 	case 'j':
45 		join = 0;
46 		break;
47 	case 'w':
48 	case 'l':
49 		length = atoi(EARGF(usage()));
50 		break;
51 	default:
52 		usage();
53 	}ARGEND
54 
55 	if(length <= indent){
56 		fprint(2, "%s: line length<=indentation\n", argv0);
57 		exits("length");
58 	}
59 
60 	s=getenv("tabstop");
61 	if(s!=nil && atoi(s)>0)
62 		maxtab=atoi(s);
63 	err = nil;
64 	Binit(&bout, 1, OWRITE);
65 	if(argc <= 0){
66 		Binit(&bin, 0, OREAD);
67 		fmt();
68 	}else{
69 		for(i=0; i<argc; i++){
70 			f = open(argv[i], OREAD);
71 			if(f < 0){
72 				fprint(2, "%s: can't open %s: %r\n", argv0, argv[i]);
73 				err = "open";
74 			}else{
75 				Binit(&bin, f, OREAD);
76 				fmt();
77 				Bterm(&bin);
78 				if(i != argc-1)
79 					Bputc(&bout, '\n');
80 			}
81 		}
82 	}
83 	exits(err);
84 }
85 
86 int
87 indentof(char **linep)
88 {
89 	int i, ind;
90 	char *line;
91 
92 	ind = 0;
93 	line = *linep;
94 	for(i=0; line[i]; i++)
95 		switch(line[i]){
96 		default:
97 			*linep = line;
98 			return ind;
99 		case ' ':
100 			ind++;
101 			break;
102 		case '\t':
103 			ind += maxtab;
104 			ind -= ind%maxtab;
105 			break;
106 		}
107 			
108 	/* plain white space doesn't change the indent */
109 	*linep = "";
110 	return indent;
111 }
112 
113 Word**
114 addword(Word **words, int *nwordp, char *s, int l, int indent, int bol)
115 {
116 	Word *w;
117 
118 	w = malloc(sizeof(Word)+l+1);
119 	memmove(w->text, s, l);
120 	w->text[l] = '\0';
121 	w->indent = indent;
122 	w->bol = bol;
123 	words = realloc(words, (*nwordp+1)*sizeof(Word*));
124 	words[(*nwordp)++] = w;
125 	return words;
126 }
127 
128 Word**
129 parseline(char *line, Word **words, int *nwordp)
130 {
131 	int ind, l, bol;
132 
133 	ind = indentof(&line);
134 	indent = ind;
135 	bol = 1;
136 	for(;;){
137 		/* find next word */
138 		while(*line==' ' || *line=='\t')
139 			line++;
140 		if(*line == '\0'){
141 			if(bol)
142 				return addword(words, nwordp, "", 0, -1, bol);
143 			break;
144 		}
145 		/* how long is this word? */
146 		for(l=0; line[l]; l++)
147 			if(line[l]==' ' || line[l]=='\t')
148 				break;
149 		words = addword(words, nwordp, line, l, indent, bol);
150 		bol = 0;
151 		line += l;
152 	}
153 	return words;
154 }
155 
156 void
157 printindent(int w)
158 {
159 	while(w >= maxtab){
160 		Bputc(&bout, '\t');
161 		w -= maxtab;
162 	}
163 	while(w > 0){
164 		Bputc(&bout, ' ');
165 		w--;
166 	}
167 }
168 
169 /* give extra space if word ends with period, etc. */
170 int
171 nspaceafter(char *s)
172 {
173 	int n;
174 
175 	n = strlen(s);
176 	if(n < 2)
177 		return 1;
178 	if(isupper((uchar)s[0]) && n < 4)
179 		return 1;
180 	if(strchr(".!?", s[n-1]) != nil)
181 		return 2;
182 	return 1;
183 }
184 	
185 
186 void
187 printwords(Word **w, int nw)
188 {
189 	int i, j, n, col, nsp;
190 
191 	/* one output line per loop */
192 	for(i=0; i<nw; ){
193 		/* if it's a blank line, print it */
194 		if(w[i]->indent == -1){
195 			Bputc(&bout, '\n');
196 			if(++i == nw)	/* out of words */
197 				break;
198 		}
199 		/* emit leading indent */
200 		col = extraindent+w[i]->indent;
201 		printindent(col);
202 		/* emit words until overflow; always emit at least one word */
203 		for(n=0;; n++){
204 			Bprint(&bout, "%s", w[i]->text);
205 			col += utflen(w[i]->text);
206 			if(++i == nw)
207 				break;	/* out of words */
208 			if(w[i]->indent != w[i-1]->indent)
209 				break;	/* indent change */
210 			nsp = nspaceafter(w[i-1]->text);
211 			if(col+nsp+utflen(w[i]->text) > extraindent+length)
212 				break;	/* fold line */
213 			if(!join && n != 0 && w[i]->bol)
214 				break;
215 			for(j=0; j<nsp; j++)
216 				Bputc(&bout, ' ');	/* emit space; another word will follow */
217 			col += nsp;
218 		}
219 		/* emit newline */
220 		Bputc(&bout, '\n');
221 	}
222 }
223 
224 void
225 fmt(void)
226 {
227 	char *s;
228 	int i, nw;
229 	Word **w;
230 
231 	nw = 0;
232 	w = nil;
233 	while((s = Brdstr(&bin, '\n', 1)) != nil){
234 		w = parseline(s, w, &nw);
235 		free(s);
236 	}
237 	printwords(w, nw);
238 	for(i=0; i<nw; i++)
239 		free(w[i]);
240 	free(w);
241 }