1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
|
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1992-2010 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* David Korn
* AT&T Bell Laboratories
*
* fold
*/
static const char usage[] =
"[-?\n@(#)$Id: fold (AT&T Research) 2004-11-18 $\n]"
USAGE_LICENSE
"[+NAME?fold - fold lines]"
"[+DESCRIPTION?\bfold\b is a filter that folds lines from its input, "
"breaking the lines to have a maximum of \awidth\a column "
"positions (or bytes if the \b-b\b option is specified). Lines "
"are broken by the insertion of a newline character such that "
"each output line is the maximum width possible that does not "
"exceed the specified number of column positions, (or bytes). A line "
"will not be broken in the middle of a character.] "
"[+?Unless the \b-b\b option is specified, the following will be treated "
"specially:]{"
"[+carriage-return?The current count of line width will be set "
"to zero. \bfold\b will not insert a newline immediately "
"before or after a carriage-return.]"
"[+backspace?If positive, the current count of line width will be "
"decremented by one. \bfold\b will not insert a newline "
"immediately before or after a backspace.]"
"[+tab?Each tab character encountered will advance the column "
"position to the next tab stop. Tab stops are at each "
"column position \an\a, where \an\a modulo 8 equals 1.]"
"}"
"[+?If no \afile\a is given, or if the \afile\a is \b-\b, \bfold\b "
"reads from standard input. The start of the file is defined "
"as the current offset.]"
"[b:bytes?Count bytes rather than columns so that each carriage-return, "
"backspace, and tab counts as 1.]"
"[c:continue?Emit \atext\a at line splits.]:[text:='\\n']"
"[d:delimiter?Break at \adelim\a boundaries.]:[delim]"
"[s:spaces?Break at word boundaries. If the line contains any blanks, "
"(spaces or tabs), within the first \awidth\a column positions or "
"bytes, the line is broken after the last blank meeting the "
"\awidth\a constraint.]"
"[w:width]#[width:=80?Use a maximum line length of \awidth\a columns "
"instead of the default.]"
"\n"
"\n[file ...]\n"
"\n"
"[+EXIT STATUS?]{"
"[+0?All files processed successfully.]"
"[+>0?An error occurred.]"
"}"
"[+SEE ALSO?\bpaste\b(1)]"
;
#include <cmd.h>
#define WIDTH 80
#define TABSIZE 8
#define T_EOF 1
#define T_NL 2
#define T_BS 3
#define T_TAB 4
#define T_SP 5
#define T_RET 6
static void fold(Sfio_t *in, Sfio_t *out, register int width, const char *cont, size_t contsize, char *cols)
{
register char *cp, *first;
register int n, col=0, x=0;
register char *last_space=0;
cols[0] = 0;
for (;;)
{
if (!(cp = sfgetr(in,'\n',0)))
{
if (!(cp = sfgetr(in,'\n',-1)) || (n = sfvalue(in)) <= 0)
break;
x = cp[--n];
cp[n] = '\n';
}
/* special case -b since no column adjustment is needed */
if(cols['\b']==0 && (n=sfvalue(in))<=width)
{
sfwrite(out,cp,n);
continue;
}
first = cp;
col = 0;
last_space = 0;
for(;;)
{
while((n=cols[*(unsigned char*)cp++])==0);
while((cp-first) > (width-col))
{
if(last_space)
col = last_space - first;
else
col = width-col;
sfwrite(out,first,col);
first += col;
col = 0;
last_space = 0;
if(cp>first+1 || (n!=T_NL && n!=T_BS))
sfwrite(out, cont, contsize);
}
switch(n)
{
case T_NL:
if(x)
*(cp-1) = x;
break;
case T_RET:
col = 0;
continue;
case T_BS:
if((cp+(--col)-first)>0)
col--;
continue;
case T_TAB:
n = (TABSIZE-1) - (cp+col-1-first)&(TABSIZE-1);
col +=n;
if((cp-first) > (width-col))
{
sfwrite(out,first,(--cp)-first);
sfwrite(out, cont, contsize);
first = cp;
col = TABSIZE-1;
last_space = 0;
continue;
}
if(cols[' '])
last_space = cp;
continue;
case T_SP:
last_space = cp;
continue;
default:
continue;
}
break;
}
sfwrite(out,first,cp-first);
}
}
int
b_fold(int argc, char *argv[], void* context)
{
register int n, width=WIDTH;
register Sfio_t *fp;
register char *cp;
char *cont="\n";
size_t contsize = 1;
char cols[1<<CHAR_BIT];
cmdinit(argc, argv, context, ERROR_CATALOG, 0);
memset(cols, 0, sizeof(cols));
cols['\t'] = T_TAB;
cols['\b'] = T_BS;
cols['\n'] = T_NL;
cols['\r'] = T_RET;
for (;;)
{
switch (optget(argv, usage))
{
case 0:
break;
case 'b':
cols['\r'] = cols['\b'] = 0;
cols['\t'] = cols[' '];
continue;
case 'c':
contsize = stresc(cont = strdup(opt_info.arg));
continue;
case 'd':
if (n = *opt_info.arg)
cols[n] = T_SP;
continue;
case 's':
cols[' '] = T_SP;
if(cols['\t']==0)
cols['\t'] = T_SP;
continue;
case 'w':
if ((width = opt_info.num) <= 0)
error(2, "%d: width must be positive", opt_info.num);
continue;
case ':':
error(2, "%s", opt_info.arg);
continue;
case '?':
error(ERROR_usage(2), "%s", opt_info.arg);
continue;
}
break;
}
argv += opt_info.index;
argc -= opt_info.index;
if(error_info.errors)
error(ERROR_usage(2),"%s", optusage(NiL));
if(cp = *argv)
argv++;
do
{
if(!cp || streq(cp,"-"))
fp = sfstdin;
else if(!(fp = sfopen(NiL,cp,"r")))
{
error(ERROR_system(0),"%s: cannot open",cp);
error_info.errors = 1;
continue;
}
fold(fp,sfstdout,width,cont,contsize,cols);
if(fp!=sfstdin)
sfclose(fp);
}
while(cp= *argv++);
return(error_info.errors);
}
|
