common/sh/bash.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1982-2011 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                  David Korn <dgk@research.att.com>                   *
*                                                                      *
***********************************************************************/
/*
 * bash specific extensions
 * originally provided by Karsten Fleischer
 */

#include "defs.h"
#include "path.h"
#include "io.h"
#include "builtins.h"
#include "name.h"

#ifndef BASH_MAJOR
#   define BASH_MAJOR   "1"
#   define BASH_MINOR   "0"
#   define BASH_PATCH   "0"
#   define BASH_BUILD   "0"
#   define BASH_RELEASE "experimental"
#endif
#define BASH_VERSION    BASH_MAJOR "." BASH_MINOR "." BASH_PATCH "(" BASH_BUILD ")-" BASH_RELEASE


extern const char   bash_pre_rc[];

static char *login_files[4];

const char sh_bash1[] =
    "[B?Enable brace group expansion. This option is only availabe in bash "
    "compatibility mode. In ksh mode, brace group expansion is always on.]"
    "[P?Do not follow symbolic links, use physical directory structure "
    "instead. Only available in bash compatibility mode.]";
const char sh_bash2[] =
"[O]:?[shopt_option?\ashopt_option\a is one of the shell options accepted by "
    "the \bshopt\b builtin. If \ashopt_option\a is present, \b-O\b sets "
    "the value of that option; \b+O\b unsets it. If \ashopt_option\a is "
    "not supplied, the names and values of the shell options accepted by "
    "\bshopt\b are printed on the standard output. If the invocation "
    "option is \b+O\b, the output is displayed in a format that may be "
    "reused as input. Only available if invoked as \bbash\b.]"
"[01:init-file|rcfile]:[file?Execute commands from \afile\a instead of the "
    "standard personal initialization file ~/.bashrc if the shell is "
    "interactive. Only available if invoked as \bbash\b.]"
"[02:editing?For option compatibility with \bbash\b only. Ignored.]"
"[03:profile?Read either the system-wide startup file or any of the "
    "personal initialization files. On by default for interactive "
    "shells. Only available if invoked as \bbash\b.]"
"[04:posix?If invoked as \bbash\b, turn on POSIX compatibility. \bBash\b in "
    "POSIX mode is not the same as \bksh\b.]"
"[05:version?Print version number and exit.]";

const char sh_optshopt[] =
"+[-1c?\n@(#)$Id: shopt (AT&T Research) 2003-02-13 $\n]"
"[-author?Karsten Fleischer <K.Fleischer@omnium.de>]"
USAGE_LICENSE
"[+NAME?shopt - set/unset variables controlling optional shell behavior]"
"[+DESCRIPTION?\bshopt\b sets or unsets variables controlling optional shell "
    "behavior. With no options, or with the \b-p\b option, a list of all "
    "settable options is displayed, with an indication of whether or not "
    "each is set.]"
"[p?Causes output to be displayed in a form that may be reused as input.]"
"[s?Set each \aoptname\a.]"
"[u?Unset each \aoptname\a.]"
"[q?Suppress output (quiet mode). The return status indicates whether the "
    "\aoptname\a is set or unset. If multiple \aoptname\a arguments are "
    "given with \b-q\b, the return status is zero if all \aoptname\as are "
    "enabled; non-zero otherwise.]"
"[o?Restricts the values of \aoptname\a to be those defined for the \b-o\b "
    "option to the set builtin.]"
"[+?If either \b-s\b or \b-u\b is used with no \aoptname\a arguments, the "
    "display is limited to those options which are set or unset.]"
"[+?\bshopt\b supports all bash options. Some settings do not have any effect "
    "or are are always on and cannot be changed.]"
"[+?The value of \aoptname\a must be one of the following:]{"
        "[+cdable_vars?If set, arguments to the \bcd\b command are "
            "assumed to be names of variables whose values are to "
            "be used if the usual \bcd\b proceeding fails.]"
        "[+cdspell?Currently ignored.]"
        "[+checkhash?Always on.]"
        "[+checkwinsize?Currently ignored.]"
        "[+cmdhist?Always on.]"
        "[+dotglob?If set, include filenames beginning with a \b.\b "
            "in the results of pathname expansion.]"
        "[+execfail?Always on.]"
        "[+expand_aliases?Always on.]"
        "[+extglob?Enable extended pattern matching features.]"
        "[+histappend?Always on.]"
        "[+histreedit?If set and an edit mode is selected, the user "
            "is given the opportunity to re-edit a failed history "
            "substitution.]"
        "[+histverify?If set and an edit mode is selected, the result "
            "of a history substitution will not be executed "
            "immediately but be placed in the edit buffer for "
            "further modifications.]"
        "[+hostcomplete?Currently ignored.]"
        "[+huponexit?Currently ignored.]"
        "[+interactive_comments?Always on.]"
        "[+lithist?Always on.]"
        "[+login_shell?This option is set if the shell is started as "
            "a login shell. The value cannot be changed.]"
        "[+mailwarn?Currently ignored.]"
        "[+no_empty_cmd_completion?Always on.]"
        "[+nocaseglob?Match filenames in a case-insensitive fashion "
            "when performing filename expansion.]"
        "[+nullglob?Allows filename patterns which match no files to "
            "expand to a null string, rather than themselves.]"
        "[+progcomp?Currently ignored.]"
        "[+promptvars?Currently ignored.]"
        "[+restricted_shell?This option is set if the shell is started "
            "as a restricted shell. The value cannot be changed. "
            "It is not reset during execution of startup files, "
            "allowing the startup files to determine whether the "
            "shell is restricted.]"
        "[+shift_verbose?Currently ignored.]"
        "[+sourcepath?If set, the \b.\b builtin uses the value of PATH "
            "to find the directory containing the file supplied "
            "as an argument.]"
        "[+xpg_echo?If set, the \becho\b and \bprint\b builtins "
            "expand backslash-escape sequences.]"
"}"
"\n"
"\n[optname ...]\n"
"\n"
"[+EXIT STATUS?]{"
    "[+?The return status when listing options is zero if all \aoptnames\a "
    "are enabled, non-zero otherwise. When setting or unsetting options, "
    "the return status is zero unless an \aoptname\a is not a valid shell "
    "option.]"
"}"

"[+SEE ALSO?\bset\b(1)]"
;

/* GLOBIGNORE discipline. Turn on SH_DOTGLOB on set, turn off on unset. */

static void put_globignore(register Namval_t* np, const char *val, int flags, Namfun_t *fp)
{
    if(val)
        sh_onoption(SH_DOTGLOB);
    else
        sh_offoption(SH_DOTGLOB);

    nv_putv(np,val,flags,fp);
}

const Namdisc_t SH_GLOBIGNORE_disc  = { sizeof(Namfun_t), put_globignore };

/* FUNCNAME discipline */

struct  funcname
{
    Namfun_t    hdr;
};

static void put_funcname(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    /* bash silently returns with an error when FUNCNAME is set,
       unsetting FUNCNAME is allowed */
    if(val && !(flags&NV_RDONLY))
        error_info.exit(1);

    nv_putv(np,val,flags,fp);
}

const Namdisc_t SH_FUNCNAME_disc  = { sizeof(struct funcname), put_funcname };

#define SET_SET     1
#define SET_UNSET   2
#define SET_NOARGS  4

/* shopt builtin */

int     b_shopt(int argc,register char *argv[],void *extra)
{
        Shell_t *shp = (Shell_t*)extra;
    int n, f, ret=0;
    Shopt_t newflags=shp->options, opt;
    int verbose=PRINT_SHOPT|PRINT_ALL|PRINT_NO_HEADER|PRINT_VERBOSE;
    int setflag=0, quietflag=0, oflag=0;
    memset(&opt,0,sizeof(opt));
#if SHOPT_RAWONLY
    on_option(&newflags,SH_VIRAW);
#endif
    while((n = optget(argv,sh_optshopt)))
    {
        switch(n)
        {
        case 'p':
            verbose&=~PRINT_VERBOSE;
            break;
        case 's':
        case 'u':
            setflag|=n=='s'?SET_SET:SET_UNSET;
            if(setflag==(SET_SET|SET_UNSET))
            {
                errormsg(SH_DICT,ERROR_ERROR,"cannot set and unset options simultaneously");
                error_info.errors++;
            }
            break;
        case 'q':
            quietflag=1;
            break;
        case 'o':
            oflag=1;
            verbose&=~PRINT_SHOPT;
            break;
        case ':':
            errormsg(SH_DICT,2, "%s", opt_info.arg);
            continue;
        case '?':
            errormsg(SH_DICT,ERROR_usage(0), "%s", opt_info.arg);
            return(-1);
        }
    }
    if(error_info.errors)
        errormsg(SH_DICT,ERROR_usage(2),"%s",optusage(NIL(char*)));
    argc -= opt_info.index;
    if(argc==0)
    {
        /* no args, -s => mask=current options, -u mask=~(current options)
           else mask=all bits */
        if(setflag&SET_SET)
            opt=newflags;
        else if(setflag&SET_UNSET)
            for(n=0;n<4;n++)
                opt.v[n]=~newflags.v[n];
        else
            memset(&opt,0xff,sizeof(opt));
        setflag=SET_NOARGS;
    }
    while(argc>0)
    {
        f=1;
        n=sh_lookopt(argv[opt_info.index],&f);
        if(n<=0||(setflag
            && (is_option(&opt,SH_INTERACTIVE)
                || is_option(&opt,SH_RESTRICTED)
                || is_option(&opt,SH_RESTRICTED2)
                || is_option(&opt,SH_BASH)
                || is_option(&opt,SH_LOGIN_SHELL)))
            ||(oflag&&(n&SH_BASHOPT)))
        {
            errormsg(SH_DICT,ERROR_ERROR, e_option, argv[opt_info.index]);
            error_info.errors++;
            ret=1;
        }
        else if(f)
            on_option(&opt,n&0xff);
        else
            off_option(&opt,n&0xff);
        opt_info.index++;
        argc--;
    }
    if(setflag&(SET_SET|SET_UNSET))
    {
        if(setflag&SET_SET)
        {
            if(sh_isoption(SH_INTERACTIVE))
                off_option(&opt,SH_NOEXEC);
            if(is_option(&opt,SH_VI)||is_option(&opt,SH_EMACS)||is_option(&opt,SH_GMACS))
            {
                off_option(&newflags,SH_VI);
                off_option(&newflags,SH_EMACS);
                off_option(&newflags,SH_GMACS);
            }
            for(n=0;n<4;n++)
                newflags.v[n] |= opt.v[n];
        }
        else if(setflag&SET_UNSET)
            for(n=0;n<4;n++)
                newflags.v[n] &= ~opt.v[n];
        sh_applyopts(shp,newflags);
        shp->options = newflags;
        if(is_option(&newflags,SH_XTRACE))
            sh_trace(shp,argv,1);
    }
    else if(!(setflag&SET_NOARGS)) /* no -s,-u but args, ret=0 if opt&mask==mask */
    {
        for(n=0;n<4;n++)
            ret+=((newflags.v[n]&opt.v[n])!=opt.v[n]);
    }
    if(!quietflag&&!(setflag&(SET_SET|SET_UNSET)))
        sh_printopts(newflags,verbose,&opt);
    return(ret);
}

/* mode = 0: init, called two times
        before parsing shell args with SH_PREINIT state turned on
    second time after sh_init() is through and with SH_PREINIT state turned off
   mode > 1: re-init
   mode < 0: shutdown
*/

void bash_init(Shell_t *shp,int mode)
{
    Sfio_t      *iop;
    Namval_t    *np;
    int     n=0,xtrace,verbose;
    if(mode>0)
        goto reinit;
    if(mode < 0)
    {
        /* termination code */
        if(sh_isoption(SH_LOGIN_SHELL) && !sh_isoption(SH_POSIX))
            sh_source(shp, NiL, sh_mactry(shp,(char*)e_bash_logout));
        return;
    }

    if(sh_isstate(SH_PREINIT))
    {   /* pre-init stage */
        if(sh_isoption(SH_RESTRICTED))
            sh_onoption(SH_RESTRICTED2);
        sh_onoption(SH_HISTORY2);
        sh_onoption(SH_INTERACTIVE_COMM);
        sh_onoption(SH_SOURCEPATH);
        sh_onoption(SH_HISTAPPEND);
        sh_onoption(SH_CMDHIST);
        sh_onoption(SH_LITHIST);
        sh_onoption(SH_NOEMPTYCMDCOMPL);
        if(shp->login_sh==2)
            sh_onoption(SH_LOGIN_SHELL);
        if(strcmp(astconf("CONFORMANCE",0,0),"standard")==0)
            sh_onoption(SH_POSIX);
        if(strcmp(astconf("UNIVERSE",0,0),"att")==0)
            sh_onoption(SH_XPG_ECHO);
        else
            sh_offoption(SH_XPG_ECHO);
        if(strcmp(astconf("PATH_RESOLVE",0,0),"physical")==0)
            sh_onoption(SH_PHYSICAL);
        else
            sh_offoption(SH_PHYSICAL);

        /* add builtins */
        sh_addbuiltin("shopt", b_shopt, &sh);

        /* set up some variables needed for --version
         * needs to go here because --version option is parsed before the init script.
         */
        if(np=nv_open("HOSTTYPE",shp->var_tree,0))
            nv_putval(np, BASH_HOSTTYPE, NV_NOFREE);
        if(np=nv_open("MACHTYPE",shp->var_tree,0))
            nv_putval(np, BASH_MACHTYPE, NV_NOFREE);
        if(np=nv_open("BASH_VERSION",shp->var_tree,0))
            nv_putval(np, BASH_VERSION, NV_NOFREE);
        if(np=nv_open("BASH_VERSINFO",shp->var_tree,0))
        {
            char *argv[7];
            argv[0] = BASH_MAJOR;
            argv[1] = BASH_MINOR;
            argv[2] = BASH_PATCH;
            argv[3] = BASH_BUILD;
            argv[4] = BASH_RELEASE;
            argv[5] = BASH_MACHTYPE;
            argv[6] = 0;
            nv_setvec(np, 0, 6, argv);
            nv_onattr(np,NV_RDONLY);
        }
        return;
    }

    /* rest of init stage */

    /* restrict BASH_ENV */
    if(np=nv_open("BASH_ENV",shp->var_tree,0))
    {
        const Namdisc_t *dp = nv_discfun(NV_DCRESTRICT);
        Namfun_t *fp = calloc(dp->dsize,1);
        fp->disc = dp;
        nv_disc(np, fp, 0);
    }

    /* open GLOBIGNORE node */
    if(np=nv_open("GLOBIGNORE",shp->var_tree,0))
    {
        const Namdisc_t *dp = &SH_GLOBIGNORE_disc;
        Namfun_t *fp = calloc(dp->dsize,1);
        fp->disc = dp;
        nv_disc(np, fp, 0);
    }

    /* set startup files */
    n=0;
    if(sh_isoption(SH_LOGIN_SHELL))
    {
        if(!sh_isoption(SH_POSIX))
        {
            login_files[n++] = (char*)e_bash_profile;
            login_files[n++] = (char*)e_bash_login;
        }
        login_files[n++] = (char*)e_profile;
    }
    shp->login_files = login_files;
reinit:
    xtrace = sh_isoption(SH_XTRACE);
    sh_offoption(SH_XTRACE);
    verbose = sh_isoption(SH_VERBOSE);
    sh_offoption(SH_VERBOSE);
    if(np = nv_open("SHELLOPTS", shp->var_tree, NV_NOADD))
        nv_offattr(np,NV_RDONLY);
    iop = sfopen(NULL, bash_pre_rc, "s");
    sh_eval(iop,0);
    if(xtrace)
        sh_offoption(SH_XTRACE);
    if(verbose)
        sh_offoption(SH_VERBOSE);
}