| 1 | # |
| 2 | |
| 3 | #include "rcv.h" |
| 4 | |
| 5 | /* |
| 6 | * Mail -- a mail program |
| 7 | * |
| 8 | * Variable handling stuff. |
| 9 | */ |
| 10 | |
| 11 | static char *SccsId = "@(#)vars.c 2.1 %G%"; |
| 12 | |
| 13 | /* |
| 14 | * Assign a value to a variable. |
| 15 | */ |
| 16 | |
| 17 | assign(name, value) |
| 18 | char name[], value[]; |
| 19 | { |
| 20 | register struct var *vp; |
| 21 | register int h; |
| 22 | |
| 23 | h = hash(name); |
| 24 | vp = lookup(name); |
| 25 | if (vp == NOVAR) { |
| 26 | vp = (struct var *) calloc(sizeof *vp, 1); |
| 27 | vp->v_name = vcopy(name); |
| 28 | vp->v_link = variables[h]; |
| 29 | variables[h] = vp; |
| 30 | } |
| 31 | else |
| 32 | vfree(vp->v_value); |
| 33 | vp->v_value = vcopy(value); |
| 34 | } |
| 35 | |
| 36 | /* |
| 37 | * Free up a variable string. We do not bother to allocate |
| 38 | * strings whose value is "" since they are expected to be frequent. |
| 39 | * Thus, we cannot free same! |
| 40 | */ |
| 41 | |
| 42 | vfree(cp) |
| 43 | register char *cp; |
| 44 | { |
| 45 | if (!equal(cp, "")) |
| 46 | cfree(cp); |
| 47 | } |
| 48 | |
| 49 | /* |
| 50 | * Copy a variable value into permanent (ie, not collected after each |
| 51 | * command) space. Do not bother to alloc space for "" |
| 52 | */ |
| 53 | |
| 54 | char * |
| 55 | vcopy(str) |
| 56 | char str[]; |
| 57 | { |
| 58 | register char *top, *cp, *cp2; |
| 59 | |
| 60 | if (equal(str, "")) |
| 61 | return(""); |
| 62 | top = calloc(strlen(str)+1, 1); |
| 63 | cp = top; |
| 64 | cp2 = str; |
| 65 | while (*cp++ = *cp2++) |
| 66 | ; |
| 67 | return(top); |
| 68 | } |
| 69 | |
| 70 | /* |
| 71 | * Get the value of a variable and return it. |
| 72 | * Look in the environment if its not available locally. |
| 73 | */ |
| 74 | |
| 75 | char * |
| 76 | value(name) |
| 77 | char name[]; |
| 78 | { |
| 79 | register struct var *vp; |
| 80 | |
| 81 | if ((vp = lookup(name)) == NOVAR) |
| 82 | return(getenv(name)); |
| 83 | return(vp->v_value); |
| 84 | } |
| 85 | |
| 86 | /* |
| 87 | * Locate a variable and return its variable |
| 88 | * node. |
| 89 | */ |
| 90 | |
| 91 | struct var * |
| 92 | lookup(name) |
| 93 | char name[]; |
| 94 | { |
| 95 | register struct var *vp; |
| 96 | register int h; |
| 97 | |
| 98 | h = hash(name); |
| 99 | for (vp = variables[h]; vp != NOVAR; vp = vp->v_link) |
| 100 | if (equal(vp->v_name, name)) |
| 101 | return(vp); |
| 102 | return(NOVAR); |
| 103 | } |
| 104 | |
| 105 | /* |
| 106 | * Locate a group name and return it. |
| 107 | */ |
| 108 | |
| 109 | struct grouphead * |
| 110 | findgroup(name) |
| 111 | char name[]; |
| 112 | { |
| 113 | register struct grouphead *gh; |
| 114 | register int h; |
| 115 | |
| 116 | h = hash(name); |
| 117 | for (gh = groups[h]; gh != NOGRP; gh = gh->g_link) |
| 118 | if (equal(gh->g_name, name)) |
| 119 | return(gh); |
| 120 | return(NOGRP); |
| 121 | } |
| 122 | |
| 123 | /* |
| 124 | * Print a group out on stdout |
| 125 | */ |
| 126 | |
| 127 | printgroup(name) |
| 128 | char name[]; |
| 129 | { |
| 130 | register struct grouphead *gh; |
| 131 | register struct group *gp; |
| 132 | |
| 133 | if ((gh = findgroup(name)) == NOGRP) { |
| 134 | printf("\"%s\": not a group\n", name); |
| 135 | return; |
| 136 | } |
| 137 | printf("%s\t", gh->g_name); |
| 138 | for (gp = gh->g_list; gp != NOGE; gp = gp->ge_link) |
| 139 | printf(" %s", gp->ge_name); |
| 140 | printf("\n"); |
| 141 | } |
| 142 | |
| 143 | /* |
| 144 | * Hash the passed string and return an index into |
| 145 | * the variable or group hash table. |
| 146 | */ |
| 147 | |
| 148 | hash(name) |
| 149 | char name[]; |
| 150 | { |
| 151 | register int h; |
| 152 | register char *cp; |
| 153 | |
| 154 | for (cp = name, h = 0; *cp; h = (h << 2) + *cp++) |
| 155 | ; |
| 156 | h &= ~0100000; |
| 157 | return(h % HSHSIZE); |
| 158 | } |