source: trunk/athena/bin/cxref/docxref.c @ 13596

/*
** docxref.c
**
** Driver for lex based scanner.  Arranges for stdin to be each named
** file in turn, so that yylex() never has to know about files.
** Some of this code is not pretty, but it's not too bad.
**
** Arnold Robbins, Information and Computer Science, Georgia Tech
**      gatech!arnold
** Copyright (c) 1984 by Arnold Robbins.
** All rights reserved.
** This program may not be sold, but may be distributed
** provided this header is included.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <libgen.h>

#define TRUE    1
#define FALSE   0

extern char yytext[];
extern int yyleng;
extern void yylex(void);

int line_no = 1;        /* current line number */
char *fname = NULL;     /* current file name */

static void usage(char *name);

int main(int argc, char **argv)
{
        FILE saved_in, *fp;
        char *name;
        int more_input = FALSE;         /* more files to process */
        int read_stdin = FALSE;

        name = basename(argv[0]);       /* save command name */
        fname = "stdin";                /* assume stdin */

        if(argc == 1)
        {
                yylex();
                exit(0);
        }

        if(argv[1][0] == '-' && argv[1][1] != '\0')
                        usage(argv[0]); /* will exit */

        saved_in = *stdin;
        /* save stdin in case "-" is found in middle of command line */

        for(--argc, argv++; argc > 0; --argc, argv++)
        {
                if(fileno(stdin) != fileno((&saved_in)) || read_stdin)
                        fclose(stdin);
                /* free unix file descriptors */

                if(strcmp(*argv, "-") == 0)
                {
                        *stdin = saved_in;
                        fname = "stdin";
                        read_stdin = TRUE;
                        more_input = (argc - 1 > 0);
                }
                else if((fp = fopen(*argv,"r")) == NULL)
                {
                        fprintf(stderr,"%s: can't open %s\n", name, *argv);
                        continue;
                }
                else
                {
                        *stdin = *fp;
                        /* do it this way so that yylex() */
                        /* never knows about files etc. */
                        more_input = (argc - 1 > 0);
                        fname = *argv;
                }

                yylex();        /* do the work */

                if(more_input)
                        line_no = 1;
        }
        return(0);
}

static void usage(char *name)
{
        fprintf(stderr,"usage: %s [files]\n", name);
        exit(1);
}