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eval.c
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C/C++ Source or Header
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1986-11-20
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10KB
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298 lines
/*
* eval.c
* Facility: m4 macro processor
* by: oz
*/
#include "mdef.h"
#include "extr.h"
extern ndptr lookup();
extern char *strsave();
extern char *mktemp();
/*
* eval - evaluate built-in macros.
* argc - number of elements in argv.
* argv - element vector :
* argv[0] = definition of a user
* macro or nil if built-in.
* argv[1] = name of the macro or
* built-in.
* argv[2] = parameters to user-defined
* . macro or built-in.
* .
*
* Note that the minimum value for argc is 3. A call in the form
* of macro-or-builtin() will result in:
* argv[0] = nullstr
* argv[1] = macro-or-builtin
* argv[2] = nullstr
*
*/
int eval (argv, argc, td)
register char *argv[];
register int argc;
register int td;
{
register int c, n;
static int sysval;
#ifdef DEBUG
printf("argc = %d\n", argc);
for (n = 0; n < argc; n++)
printf("argv[%d] = %s\n", n, argv[n]);
#endif
/*
* if argc == 3 and argv[2] is null,
* then we have macro-or-builtin() type call.
* We adjust argc to avoid further checking..
*
*/
if (argc == 3 && !*(argv[2]))
argc--;
switch (td & ~STATIC) {
case DEFITYPE:
if (argc > 2)
dodefine(argv[2], (argc > 3) ? argv[3] : null);
break;
case PUSDTYPE:
if (argc > 2)
dopushdef(argv[2], (argc > 3) ? argv[3] : null);
break;
case DUMPTYPE:
dodump(argv, argc);
break;
case EXPRTYPE:
/*
* doexpr - evaluate arithmetic expression
*
*/
if (argc > 2)
pbnum(expr(argv[2]));
break;
case IFELTYPE:
if (argc > 4)
doifelse(argv, argc);
break;
case IFDFTYPE:
/*
* doifdef - select one of two alternatives based
* on the existence of another definition
*/
if (argc > 3) {
if (lookup(argv[2]) != nil)
pbstr(argv[3]);
else if (argc > 4)
pbstr(argv[4]);
}
break;
case LENGTYPE:
/*
* dolen - find the length of the argument
*
*/
if (argc > 2)
pbnum((argc > 2) ? strlen(argv[2]) : 0);
break;
case INCRTYPE:
/*
* doincr - increment the value of the argument
*
*/
if (argc > 2)
pbnum(atoi(argv[2]) + 1);
break;
case DECRTYPE:
/*
* dodecr - decrement the value of the argument
*
*/
if (argc > 2)
pbnum(atoi(argv[2]) - 1);
break;
#if unix || vms
case SYSCTYPE:
/*
* dosys - execute system command
*
*/
if (argc > 2)
sysval = system(argv[2]);
break;
case SYSVTYPE:
/*
* dosysval - return value of the last system call.
*
*/
pbnum(sysval);
break;
#endif
case INCLTYPE:
if (argc > 2)
if (!doincl(argv[2])) {
fprintf(stderr,"m4: %s: ",argv[2]);
error("cannot open for read.");
}
break;
case SINCTYPE:
if (argc > 2)
(void) doincl(argv[2]);
break;
#ifdef EXTENDED
case PASTTYPE:
if (argc > 2)
if (!dopaste(argv[2])) {
fprintf(stderr,"m4: %s: ",argv[2]);
error("cannot open for read.");
}
break;
case SPASTYPE:
if (argc > 2)
(void) dopaste(argv[2]);
break;
#endif
case CHNQTYPE:
dochq(argv, argc);
break;
case CHNCTYPE:
dochc(argv, argc);
break;
case SUBSTYPE:
/*
* dosub - select substring
*
*/
if (argc > 3)
dosub(argv,argc);
break;
case SHIFTYPE:
/*
* doshift - push back all arguments except the
* first one (i.e. skip argv[2])
*/
if (argc > 3) {
for (n = argc-1; n > 3; n--) {
putback(rquote);
pbstr(argv[n]);
putback(lquote);
putback(',');
}
putback(rquote);
pbstr(argv[3]);
putback(lquote);
}
break;
case DIVRTYPE:
if (argc > 2 && (n = atoi(argv[2])) != 0)
dodiv(n);
else {
active = stdout;
oindex = 0;
}
break;
case UNDVTYPE:
doundiv(argv, argc);
break;
case DIVNTYPE:
/*
* dodivnum - return the number of current
* output diversion
*
*/
pbnum(oindex);
break;
case UNDFTYPE:
/*
* doundefine - undefine a previously defined
* macro(s) or m4 keyword(s).
*/
if (argc > 2)
for (n = 2; n < argc; n++)
remhash(argv[n], ALL);
break;
case POPDTYPE:
/*
* dopopdef - remove the topmost definitions of
* macro(s) or m4 keyword(s).
*/
if (argc > 2)
for (n = 2; n < argc; n++)
remhash(argv[n], TOP);
break;
case MKTMTYPE:
/*
* dotemp - create a temporary file
*
*/
if (argc > 2)
pbstr(mktemp(argv[2]));
break;
case TRNLTYPE:
/*
* dotranslit - replace all characters in the
* source string that appears in
* the "from" string with the corresponding
* characters in the "to" string.
*
*/
if (argc > 3) {
char temp[MAXTOK];
if (argc > 4)
map(temp, argv[2], argv[3], argv[4]);
else
map(temp, argv[2], argv[3], null);
pbstr(temp);
}
else
if (argc > 2)
pbstr(argv[2]);
break;
case INDXTYPE:
/*
* doindex - find the index of the second argument
* string in the first argument string.
* -1 if not present.
*/
pbnum((argc > 3) ? indx(argv[2], argv[3]) : -1);
break;
case ERRPTYPE:
/*
* doerrp - print the arguments to stderr file
*
*/
if (argc > 2) {
for (n = 2; n < argc; n++)
fprintf(stderr,"%s ", argv[n]);
fprintf(stderr, "\n");
}
break;
case DNLNTYPE:
/*
* dodnl - eat-up-to and including newline
*
*/
while ((c = gpbc()) != '\n' && c != EOF)
;
break;
case M4WRTYPE:
/*
* dom4wrap - set up for wrap-up/wind-down activity
*
*/
m4wraps = (argc > 2) ? strsave(argv[2]) : null;
break;
case EXITTYPE:
/*
* doexit - immediate exit from m4.
*
*/
exit((argc > 2) ? atoi(argv[2]) : 0);
break;
case DEFNTYPE:
if (argc > 2)
for (n = 2; n < argc; n++)
dodefn(argv[n]);
break;
default:
error("m4: major botch in eval.");
break;
}
}