/*      $OpenBSD: main.c,v 1.74 2026/03/22 05:07:06 deraadt Exp $       */
/****************************************************************
Copyright (C) Lucent Technologies 1997
All Rights Reserved

Permission to use, copy, modify, and distribute this software and
its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appear in all
copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the name Lucent Technologies or any of
its entities not be used in advertising or publicity pertaining
to distribution of the software without specific, written prior
permission.

LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
THIS SOFTWARE.
****************************************************************/

const char      *version = "version 20250116";

#define DEBUG
#include <stdio.h>
#include <ctype.h>
#include <locale.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include "awk.h"

extern  char    *__progname;
extern  char    **environ;
extern  int     nfields;

int     dbg     = 0;
Awkfloat        srand_seed = 1;
char    *cmdname;       /* gets argv[0] for error messages */
extern  FILE    *yyin;  /* lex input file */
char    *lexprog;       /* points to program argument if it exists */
extern  int errorflag;  /* non-zero if any syntax errors; set by yyerror */
enum compile_states     compile_time = ERROR_PRINTING;

static char     **pfile;        /* program filenames from -f's */
static size_t   maxpfile;       /* max program filename */
static size_t   npfile;         /* number of filenames */
static size_t   curpfile;       /* current filename */

bool    CSV = false;            /* true for csv input */
bool    safe = false;           /* true => "safe" mode */
bool    do_posix = false;       /* true => POSIX mode */

size_t  awk_mb_cur_max = 1;

static noreturn void fpecatch(int n
#ifdef SA_SIGINFO
        , siginfo_t *si, void *uc
#endif
)
{
        extern Node *curnode;
#ifdef SA_SIGINFO
        const char *mesg = NULL;

        switch (si->si_code) {
        case FPE_INTDIV:
                mesg = "Integer divide by zero";
                break;
        case FPE_INTOVF:
                mesg = "Integer overflow";
                break;
        case FPE_FLTDIV:
                mesg = "Floating point divide by zero";
                break;
        case FPE_FLTOVF:
                mesg = "Floating point overflow";
                break;
        case FPE_FLTUND:
                mesg = "Floating point underflow";
                break;
        case FPE_FLTRES:
                mesg = "Floating point inexact result";
                break;
        case FPE_FLTINV:
                mesg = "Invalid Floating point operation";
                break;
        case FPE_FLTSUB:
                mesg = "Subscript out of range";
                break;
        case 0:
        default:
                mesg = "Unknown error";
                break;
        }
#endif
        dprintf(STDERR_FILENO, "floating point exception%s%s\n",
#ifdef SA_SIGINFO
                ": ", mesg
#else
                "", ""
#endif
            );

        if (compile_time != 2 && NR && *NR > 0) {
                dprintf(STDERR_FILENO, " input record number %d", (int) (*FNR));
                if (strcmp(*FILENAME, "-") != 0) {
                        dprintf(STDERR_FILENO, ", file %s", *FILENAME);
                }
                dprintf(STDERR_FILENO, "\n");
        }
        if (compile_time != 2 && curnode) {
                dprintf(STDERR_FILENO, " source line number %d", curnode->lineno);
        } else if (compile_time != 2 && lineno) {
                dprintf(STDERR_FILENO, " source line number %d", lineno);
        }
        if (compile_time == 1 && cursource() != NULL) {
                dprintf(STDERR_FILENO, " source file %s", cursource());
        }
        dprintf(STDERR_FILENO, "\n");
        if (dbg > 1)            /* core dump if serious debugging on */
                abort();
        _exit(2);
}

static const char *
setfs(char *p)
{
        /* wart: t=>\t */
        if (p[0] == 't' && p[1] == '\0')
                return "\t";
        return p;
}

static char *
getarg(int *argc, char ***argv, const char *msg)
{
        if ((*argv)[1][2] != '\0') {    /* arg is -fsomething */
                return &(*argv)[1][2];
        } else {                        /* arg is -f something */
                (*argc)--; (*argv)++;
                if (*argc <= 1)
                        FATAL("%s", msg);
                return (*argv)[1];
        }
}

int main(int argc, char *argv[])
{
        const char *fs = NULL;
        char *fn, *vn;

        setlocale(LC_CTYPE, "");
        setlocale(LC_NUMERIC, "C"); /* for parsing cmdline & prog */
        awk_mb_cur_max = MB_CUR_MAX;
        cmdname = __progname;

        if (argc == 1) {
                fprintf(stderr, "usage: %s [-safe] [-V] [-d[n]] "
                    "[-f fs | --csv] [-v var=value]\n"
                    "\t   [prog | -f progfile] file ...\n", cmdname);
                return 1;
        }
#ifdef SA_SIGINFO
        {
                struct sigaction sa;
                sa.sa_sigaction = fpecatch;
                sa.sa_flags = SA_SIGINFO;
                sigemptyset(&sa.sa_mask);
                (void)sigaction(SIGFPE, &sa, NULL);
        }
#else
        (void)signal(SIGFPE, fpecatch);
#endif

        do_posix = (getenv("POSIXLY_CORRECT") != NULL);

        yyin = NULL;
        symtab = makesymtab(NSYMTAB);
        while (argc > 1 && argv[1][0] == '-' && argv[1][1] != '\0') {
                if (strcmp(argv[1], "--version") == 0) {
                        printf("awk %s\n", version);
                        return 0;
                }
                if (strcmp(argv[1], "--") == 0) {       /* explicit end of args */
                        argc--;
                        argv++;
                        break;
                }
                if (strcmp(argv[1], "--csv") == 0) {    /* turn on csv input processing */
                        CSV = true;
                        argc--;
                        argv++;
                        continue;
                }
                switch (argv[1][1]) {
                case 's':
                        if (strcmp(argv[1], "-safe") == 0)
                                safe = true;
                        break;
                case 'f':       /* next argument is program filename */
                        fn = getarg(&argc, &argv, "no program filename");
                        if (npfile >= maxpfile) {
                                maxpfile += 20;
                                pfile = (char **) reallocarray(pfile, maxpfile, sizeof(*pfile));
                                if (pfile == NULL)
                                        FATAL("error allocating space for -f options");
                        }
                        pfile[npfile++] = fn;
                        break;
                case 'F':       /* set field separator */
                        fs = setfs(getarg(&argc, &argv, "no field separator"));
                        break;
                case 'v':       /* -v a=1 to be done NOW.  one -v for each */
                        vn = getarg(&argc, &argv, "no variable name");
                        if (isclvar(vn))
                                setclvar(vn);
                        else
                                FATAL("invalid -v option argument: %s", vn);
                        break;
                case 'd':
                        dbg = atoi(&argv[1][2]);
                        if (dbg == 0)
                                dbg = 1;
                        printf("awk %s\n", version);
                        break;
                case 'V':
                        printf("awk %s\n", version);
                        return 0;
                default:
                        WARNING("unknown option %s ignored", argv[1]);
                        break;
                }
                argc--;
                argv++;
        }

        if (safe) {
                if (unveil("/", "r") == -1) {
                        fprintf(stderr, "%s: unveil: / r\n",
                            cmdname);
                        exit(1);
                }
                if (unveil("/dev/null", "rw") == -1) {
                        fprintf(stderr, "%s: unveil: /dev/null rw\n",
                            cmdname);
                        exit(1);
                }
                if (pledge("stdio rpath wpath", NULL) == -1) {
                        fprintf(stderr, "%s: pledge: incorrect arguments\n",
                            cmdname);
                        exit(1);
                }
        } else {
                if (pledge("stdio rpath wpath cpath proc exec", NULL) == -1) {
                        fprintf(stderr, "%s: pledge: incorrect arguments\n",
                            cmdname);
                        exit(1);
                }
        }

        if (CSV && (fs != NULL || lookup("FS", symtab) != NULL))
                WARNING("danger: don't set FS when --csv is in effect");

        /* argv[1] is now the first argument */
        if (npfile == 0) {      /* no -f; first argument is program */
                if (argc <= 1) {
                        if (dbg)
                                exit(0);
                        FATAL("no program given");
                }
                DPRINTF("program = |%s|\n", argv[1]);
                lexprog = argv[1];
                argc--;
                argv++;
        }
        recinit(recsize);
        syminit();
        compile_time = COMPILING;
        argv[0] = cmdname;      /* put prog name at front of arglist */
        DPRINTF("argc=%d, argv[0]=%s\n", argc, argv[0]);
        arginit(argc, argv);
        if (!safe)
                envinit(environ);
        yyparse();
#if 0
        // Doing this would comply with POSIX, but is not compatible with
        // other awks and with what most users expect. So comment it out.
        setlocale(LC_NUMERIC, ""); /* back to whatever it is locally */
#endif
        if (fs)
                *FS = qstring(fs, '\0');
        DPRINTF("errorflag=%d\n", errorflag);
        if (errorflag == 0) {
                compile_time = RUNNING;
                run(winner);
        } else
                bracecheck();
        return(errorflag);
}

int pgetc(void)         /* get 1 character from awk program */
{
        int c;

        for (;;) {
                if (yyin == NULL) {
                        if (curpfile >= npfile)
                                return EOF;
                        if (strcmp(pfile[curpfile], "-") == 0)
                                yyin = stdin;
                        else if ((yyin = fopen(pfile[curpfile], "r")) == NULL)
                                FATAL("can't open file %s", pfile[curpfile]);
                        lineno = 1;
                }
                if ((c = getc(yyin)) != EOF)
                        return c;
                if (yyin != stdin)
                        fclose(yyin);
                yyin = NULL;
                curpfile++;
        }
}

char *cursource(void)   /* current source file name */
{
        if (npfile > 0)
                return pfile[curpfile < npfile ? curpfile : curpfile - 1];
        else
                return NULL;
}