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1.1 root 1: #ifndef lint
2: static char sccsid[] = "@(#)lex.c 4.3 9/3/83";
3: #endif
4:
5: #include "e.h"
6: #include "e.def"
7:
8: #define SSIZE 400
9: char token[SSIZE];
10: int sp;
11: #define putbak(c) *ip++ = c;
12: #define PUSHBACK 300 /* maximum pushback characters */
13: char ibuf[PUSHBACK+SSIZE]; /* pushback buffer for definitions, etc. */
14: char *ip = ibuf;
15:
16: gtc() {
17: loop:
18: if (ip > ibuf)
19: return(*--ip); /* already present */
20: lastchar = getc(curfile);
21: if (lastchar=='\n')
22: linect++;
23: if (lastchar != EOF)
24: return(lastchar);
25: if (++ifile > svargc) {
26: return(EOF);
27: }
28: fclose(curfile);
29: linect = 1;
30: if (openinfile() == 0)
31: goto loop;
32: return(EOF);
33: }
34: /*
35: * open file indexed by ifile in svargv, return non zero if fail
36: */
37: openinfile()
38: {
39: if (strcmp(svargv[ifile], "-") == 0){
40: curfile = stdin;
41: return(0);
42: } else if ((curfile=fopen(svargv[ifile], "r")) != NULL){
43: return(0);
44: }
45: error(FATAL, "can't open file %s", svargv[ifile]);
46: return(1);
47: }
48:
49: pbstr(str)
50: register char *str;
51: {
52: register char *p;
53:
54: p = str;
55: while (*p++);
56: --p;
57: if (ip >= &ibuf[PUSHBACK])
58: error( FATAL, "pushback overflow");
59: while (p > str)
60: putbak(*--p);
61: }
62:
63: yylex() {
64: register int c;
65: tbl *tp, *lookup();
66: extern tbl **keytbl, **deftbl;
67:
68: beg:
69: while ((c=gtc())==' ' || c=='\n')
70: ;
71: yylval=c;
72: switch(c) {
73:
74: case EOF:
75: return(EOF);
76: case '~':
77: return(SPACE);
78: case '^':
79: return(THIN);
80: case '\t':
81: return(TAB);
82: case '{':
83: return('{');
84: case '}':
85: return('}');
86: case '"':
87: for (sp=0; (c=gtc())!='"' && c != '\n'; ) {
88: if (c == '\\')
89: if ((c = gtc()) != '"')
90: token[sp++] = '\\';
91: token[sp++] = c;
92: if (sp>=SSIZE)
93: error(FATAL, "quoted string %.20s... too long", token);
94: }
95: token[sp]='\0';
96: yylval = (int) &token[0];
97: if (c == '\n')
98: error(!FATAL, "missing \" in %.20s", token);
99: return(QTEXT);
100: }
101: if (c==righteq)
102: return(EOF);
103:
104: putbak(c);
105: getstr(token, SSIZE);
106: if (dbg)printf(".\tlex token = |%s|\n", token);
107: if ((tp = lookup(&deftbl, token, NULL)) != NULL) {
108: putbak(' ');
109: pbstr(tp->defn);
110: putbak(' ');
111: if (dbg)
112: printf(".\tfound %s|=%s|\n", token, tp->defn);
113: }
114: else if ((tp = lookup(&keytbl, token, NULL)) == NULL) {
115: if(dbg)printf(".\t%s is not a keyword\n", token);
116: return(CONTIG);
117: }
118: else if (tp->defn == (char *) DEFINE || tp->defn == (char *) NDEFINE || tp->defn == (char *) TDEFINE)
119: define(tp->defn);
120: else if (tp->defn == (char *) DELIM)
121: delim();
122: else if (tp->defn == (char *) GSIZE)
123: globsize();
124: else if (tp->defn == (char *) GFONT)
125: globfont();
126: else if (tp->defn == (char *) INCLUDE)
127: include();
128: else {
129: return((int) tp->defn);
130: }
131: goto beg;
132: }
133:
134: getstr(s, n) char *s; register int n; {
135: register int c;
136: register char *p;
137:
138: p = s;
139: while ((c = gtc()) == ' ' || c == '\n')
140: ;
141: if (c == EOF) {
142: *s = 0;
143: return;
144: }
145: while (c != ' ' && c != '\t' && c != '\n' && c != '{' && c != '}'
146: && c != '"' && c != '~' && c != '^' && c != righteq) {
147: if (c == '\\')
148: if ((c = gtc()) != '"')
149: *p++ = '\\';
150: *p++ = c;
151: if (--n <= 0)
152: error(FATAL, "token %.20s... too long", s);
153: c = gtc();
154: }
155: if (c=='{' || c=='}' || c=='"' || c=='~' || c=='^' || c=='\t' || c==righteq)
156: putbak(c);
157: *p = '\0';
158: yylval = (int) s;
159: }
160:
161: cstr(s, quote, maxs) char *s; int quote; {
162: int del, c, i;
163:
164: while((del=gtc()) == ' ' || del == '\t' || del == '\n');
165: if (quote)
166: for (i=0; (c=gtc()) != del && c != EOF;) {
167: s[i++] = c;
168: if (i >= maxs)
169: return(1); /* disaster */
170: }
171: else {
172: s[0] = del;
173: for (i=1; (c=gtc())!=' ' && c!= '\t' && c!='\n' && c!=EOF;) {
174: s[i++]=c;
175: if (i >= maxs)
176: return(1); /* disaster */
177: }
178: }
179: s[i] = '\0';
180: if (c == EOF)
181: error(FATAL, "Unexpected end of input at %.20s", s);
182: return(0);
183: }
184:
185: define(type) int type; {
186: char *strsave(), *p1, *p2;
187: tbl *lookup();
188: extern tbl **deftbl;
189:
190: getstr(token, SSIZE); /* get name */
191: if (type != DEFINE) {
192: cstr(token, 1, SSIZE); /* skip the definition too */
193: return;
194: }
195: p1 = strsave(token);
196: if (cstr(token, 1, SSIZE))
197: error(FATAL, "Unterminated definition at %.20s", token);
198: p2 = strsave(token);
199: lookup(&deftbl, p1, p2);
200: if (dbg)printf(".\tname %s defined as %s\n", p1, p2);
201: }
202:
203: char *strsave(s)
204: char *s;
205: {
206: char *malloc();
207: register char *q;
208:
209: q = malloc(strlen(s)+1);
210: if (q == NULL)
211: error(FATAL, "out of space in strsave on %s", s);
212: strcpy(q, s);
213: return(q);
214: }
215:
216: include() {
217: error(!FATAL, "Include not yet implemented");
218: }
219:
220: delim() {
221: yyval = eqnreg = 0;
222: if (cstr(token, 0, SSIZE))
223: error(FATAL, "Bizarre delimiters at %.20s", token);
224: lefteq = token[0];
225: righteq = token[1];
226: if (lefteq == 'o' && righteq == 'f')
227: lefteq = righteq = '\0';
228: }
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