freebsd-dev/lib/libss/parse.c

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/*
* Copyright 1987, 1988 by MIT Student Information Processing Board
*
* For copyright info, see copyright.h.
*/
#include <stdlib.h>
#include "ss_internal.h"
#include "copyright.h"
#ifndef lint
static char const rcsid[] =
"Header: parse.c,v 1.1 89/01/25 07:53:13 raeburn Exp ";
#endif
enum parse_mode { WHITESPACE, TOKEN, QUOTED_STRING };
/*
* parse(line_ptr, argc_ptr)
*
* Function:
* Parses line, dividing at whitespace, into tokens, returns
* the "argc" and "argv" values.
* Arguments:
* line_ptr (char *)
* Pointer to text string to be parsed.
* argc_ptr (int *)
* Where to put the "argc" (number of tokens) value.
* Returns:
* argv (char **)
* Series of pointers to parsed tokens.
*/
#define NEW_ARGV(old,n) (char **)reallocf((char *)old,\
(unsigned)(n+2)*sizeof(char*))
char **ss_parse (sci_idx, line_ptr, argc_ptr)
int sci_idx;
register char *line_ptr;
int *argc_ptr;
{
register char **argv, *cp;
register int argc;
register enum parse_mode parse_mode;
argv = (char **) malloc (sizeof(char *));
if (argv == (char **)NULL) {
ss_error(sci_idx, errno, "Can't allocate storage");
return(argv);
}
*argv = (char *)NULL;
argc = 0;
parse_mode = WHITESPACE; /* flushing whitespace */
cp = line_ptr; /* cp is for output */
while (1) {
#ifdef DEBUG
{
printf ("character `%c', mode %d\n", *line_ptr, parse_mode);
}
#endif
while (parse_mode == WHITESPACE) {
if (*line_ptr == '\0')
goto end_of_line;
if (*line_ptr == ' ' || *line_ptr == '\t') {
line_ptr++;
continue;
}
if (*line_ptr == '"') {
/* go to quoted-string mode */
parse_mode = QUOTED_STRING;
cp = line_ptr++;
argv = NEW_ARGV (argv, argc);
argv[argc++] = cp;
argv[argc] = NULL;
}
else {
/* random-token mode */
parse_mode = TOKEN;
cp = line_ptr;
argv = NEW_ARGV (argv, argc);
argv[argc++] = line_ptr;
argv[argc] = NULL;
}
}
while (parse_mode == TOKEN) {
if (*line_ptr == '\0') {
*cp++ = '\0';
goto end_of_line;
}
else if (*line_ptr == ' ' || *line_ptr == '\t') {
*cp++ = '\0';
line_ptr++;
parse_mode = WHITESPACE;
}
else if (*line_ptr == '"') {
line_ptr++;
parse_mode = QUOTED_STRING;
}
else {
*cp++ = *line_ptr++;
}
}
while (parse_mode == QUOTED_STRING) {
if (*line_ptr == '\0') {
ss_error (sci_idx, 0,
"Unbalanced quotes in command line");
free (argv);
return NULL;
}
else if (*line_ptr == '"') {
if (*++line_ptr == '"') {
*cp++ = '"';
line_ptr++;
}
else {
parse_mode = TOKEN;
}
}
else {
*cp++ = *line_ptr++;
}
}
}
end_of_line:
*argc_ptr = argc;
#ifdef DEBUG
{
int i;
printf ("argc = %d\n", argc);
for (i = 0; i <= argc; i++)
printf ("\targv[%2d] = `%s'\n", i,
argv[i] ? argv[i] : "<NULL>");
}
#endif
return(argv);
}