Annotation of 43BSDTahoe/ucb/Mail/vars.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1980 Regents of the University of California.
        !             3:  * All rights reserved.
        !             4:  *
        !             5:  * Redistribution and use in source and binary forms are permitted
        !             6:  * provided that this notice is preserved and that due credit is given
        !             7:  * to the University of California at Berkeley. The name of the University
        !             8:  * may not be used to endorse or promote products derived from this
        !             9:  * software without specific prior written permission. This software
        !            10:  * is provided ``as is'' without express or implied warranty.
        !            11:  */
        !            12: 
        !            13: #ifdef notdef
        !            14: static char sccsid[] = "@(#)vars.c     5.4 (Berkeley) 2/18/88";
        !            15: #endif /* notdef */
        !            16: 
        !            17: #include "rcv.h"
        !            18: 
        !            19: /*
        !            20:  * Mail -- a mail program
        !            21:  *
        !            22:  * Variable handling stuff.
        !            23:  */
        !            24: 
        !            25: /*
        !            26:  * Assign a value to a variable.
        !            27:  */
        !            28: 
        !            29: assign(name, value)
        !            30:        char name[], value[];
        !            31: {
        !            32:        register struct var *vp;
        !            33:        register int h;
        !            34: 
        !            35:        h = hash(name);
        !            36:        vp = lookup(name);
        !            37:        if (vp == NOVAR) {
        !            38:                vp = (struct var *) calloc(sizeof *vp, 1);
        !            39:                vp->v_name = vcopy(name);
        !            40:                vp->v_link = variables[h];
        !            41:                variables[h] = vp;
        !            42:        }
        !            43:        else
        !            44:                vfree(vp->v_value);
        !            45:        vp->v_value = vcopy(value);
        !            46: }
        !            47: 
        !            48: /*
        !            49:  * Free up a variable string.  We do not bother to allocate
        !            50:  * strings whose value is "" since they are expected to be frequent.
        !            51:  * Thus, we cannot free same!
        !            52:  */
        !            53: 
        !            54: vfree(cp)
        !            55:        char *cp;
        !            56: {
        !            57:        if (*cp)
        !            58:                free(cp);
        !            59: }
        !            60: 
        !            61: /*
        !            62:  * Copy a variable value into permanent (ie, not collected after each
        !            63:  * command) space.  Do not bother to alloc space for ""
        !            64:  */
        !            65: 
        !            66: char *
        !            67: vcopy(str)
        !            68:        char str[];
        !            69: {
        !            70:        char *new;
        !            71:        unsigned len;
        !            72: 
        !            73:        if (*str == '\0')
        !            74:                return "";
        !            75:        len = strlen(str) + 1;
        !            76:        if ((new = malloc(len)) == NULL)
        !            77:                panic("Out of memory");
        !            78:        bcopy(str, new, (int) len);
        !            79:        return new;
        !            80: }
        !            81: 
        !            82: /*
        !            83:  * Get the value of a variable and return it.
        !            84:  * Look in the environment if its not available locally.
        !            85:  */
        !            86: 
        !            87: char *
        !            88: value(name)
        !            89:        char name[];
        !            90: {
        !            91:        register struct var *vp;
        !            92: 
        !            93:        if ((vp = lookup(name)) == NOVAR)
        !            94:                return(getenv(name));
        !            95:        return(vp->v_value);
        !            96: }
        !            97: 
        !            98: /*
        !            99:  * Locate a variable and return its variable
        !           100:  * node.
        !           101:  */
        !           102: 
        !           103: struct var *
        !           104: lookup(name)
        !           105:        register char name[];
        !           106: {
        !           107:        register struct var *vp;
        !           108: 
        !           109:        for (vp = variables[hash(name)]; vp != NOVAR; vp = vp->v_link)
        !           110:                if (*vp->v_name == *name && equal(vp->v_name, name))
        !           111:                        return(vp);
        !           112:        return(NOVAR);
        !           113: }
        !           114: 
        !           115: /*
        !           116:  * Locate a group name and return it.
        !           117:  */
        !           118: 
        !           119: struct grouphead *
        !           120: findgroup(name)
        !           121:        register char name[];
        !           122: {
        !           123:        register struct grouphead *gh;
        !           124: 
        !           125:        for (gh = groups[hash(name)]; gh != NOGRP; gh = gh->g_link)
        !           126:                if (*gh->g_name == *name && equal(gh->g_name, name))
        !           127:                        return(gh);
        !           128:        return(NOGRP);
        !           129: }
        !           130: 
        !           131: /*
        !           132:  * Print a group out on stdout
        !           133:  */
        !           134: 
        !           135: printgroup(name)
        !           136:        char name[];
        !           137: {
        !           138:        register struct grouphead *gh;
        !           139:        register struct group *gp;
        !           140: 
        !           141:        if ((gh = findgroup(name)) == NOGRP) {
        !           142:                printf("\"%s\": not a group\n", name);
        !           143:                return;
        !           144:        }
        !           145:        printf("%s\t", gh->g_name);
        !           146:        for (gp = gh->g_list; gp != NOGE; gp = gp->ge_link)
        !           147:                printf(" %s", gp->ge_name);
        !           148:        putchar('\n');
        !           149: }
        !           150: 
        !           151: /*
        !           152:  * Hash the passed string and return an index into
        !           153:  * the variable or group hash table.
        !           154:  */
        !           155: 
        !           156: hash(name)
        !           157:        register char *name;
        !           158: {
        !           159:        register h = 0;
        !           160: 
        !           161:        while (*name) {
        !           162:                h <<= 2;
        !           163:                h += *name++;
        !           164:        }
        !           165:        if (h < 0 && (h = -h) < 0)
        !           166:                h = 0;
        !           167:        return (h % HSHSIZE);
        !           168: }

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