1 | /*-
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2 | * Copyright (c) 1991 The Regents of the University of California.
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3 | * All rights reserved.
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4 | *
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5 | * This code is derived from software contributed to Berkeley by
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6 | * Kenneth Almquist.
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7 | *
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8 | * Redistribution and use in source and binary forms, with or without
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9 | * modification, are permitted provided that the following conditions
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10 | * are met:
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11 | * 1. Redistributions of source code must retain the above copyright
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12 | * notice, this list of conditions and the following disclaimer.
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13 | * 2. Redistributions in binary form must reproduce the above copyright
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14 | * notice, this list of conditions and the following disclaimer in the
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15 | * documentation and/or other materials provided with the distribution.
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16 | * 3. All advertising materials mentioning features or use of this software
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17 | * must display the following acknowledgement:
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18 | * This product includes software developed by the University of
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19 | * California, Berkeley and its contributors.
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20 | * 4. Neither the name of the University nor the names of its contributors
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21 | * may be used to endorse or promote products derived from this software
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22 | * without specific prior written permission.
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23 | *
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24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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34 | * SUCH DAMAGE.
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35 | */
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36 |
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37 | #ifndef lint
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38 | static char sccsid[] = "@(#)var.c 5.3 (Berkeley) 4/12/91";
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39 | #endif /* not lint */
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40 |
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41 | /*
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42 | * Shell variables.
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43 | */
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44 |
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45 | #include "shell.h"
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46 | #include "output.h"
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47 | #include "expand.h"
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48 | #include "nodes.h" /* for other headers */
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49 | #include "eval.h" /* defines cmdenviron */
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50 | #include "exec.h"
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51 | #include "syntax.h"
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52 | #include "options.h"
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53 | #include "mail.h"
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54 | #include "var.h"
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55 | #include "memalloc.h"
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56 | #include "error.h"
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57 | #include "mystring.h"
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58 |
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59 |
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60 | #define VTABSIZE 39
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61 |
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62 |
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63 | struct varinit {
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64 | struct var *var;
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65 | int flags;
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66 | char *text;
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67 | };
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68 |
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69 |
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70 | #if ATTY
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71 | struct var vatty;
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72 | #endif
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73 | struct var vifs;
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74 | struct var vmail;
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75 | struct var vmpath;
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76 | struct var vpath;
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77 | struct var vps1;
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78 | struct var vps2;
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79 | struct var vpse;
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80 | struct var vvers;
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81 | #if ATTY
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82 | struct var vterm;
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83 | #endif
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84 |
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85 | const struct varinit varinit[] = {
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86 | #if ATTY
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87 | {&vatty, VSTRFIXED|VTEXTFIXED|VUNSET, "ATTY="},
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88 | #endif
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89 | {&vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n"},
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90 | {&vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL="},
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91 | {&vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH="},
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92 | {&vpath, VSTRFIXED|VTEXTFIXED, "PATH=:/bin:/usr/bin"},
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93 | /*
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94 | * vps1 depends on uid
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95 | */
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96 | {&vps2, VSTRFIXED|VTEXTFIXED, "PS2=> "},
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97 | {&vpse, VSTRFIXED|VTEXTFIXED, "PSE=* "},
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98 | #if ATTY
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99 | {&vterm, VSTRFIXED|VTEXTFIXED|VUNSET, "TERM="},
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100 | #endif
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101 | {NULL, 0, NULL}
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102 | };
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103 |
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104 | struct var *vartab[VTABSIZE];
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105 |
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106 | STATIC void unsetvar __P((char *));
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107 | STATIC struct var **hashvar __P((char *));
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108 | STATIC int varequal __P((char *, char *));
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109 |
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110 | /*
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111 | * Initialize the varable symbol tables and import the environment
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112 | */
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113 |
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114 | #ifdef mkinit
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115 | INCLUDE "var.h"
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116 | INIT {
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117 | char **envp;
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118 | extern char **environ;
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119 |
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120 | initvar();
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121 | for (envp = environ ; *envp ; envp++) {
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122 | if (strchr(*envp, '=')) {
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123 | setvareq(*envp, VEXPORT|VTEXTFIXED);
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124 | }
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125 | }
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126 | }
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127 | #endif
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128 |
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129 |
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130 | /*
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131 | * This routine initializes the builtin variables. It is called when the
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132 | * shell is initialized and again when a shell procedure is spawned.
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133 | */
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134 |
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135 | void
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136 | initvar() {
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137 | const struct varinit *ip;
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138 | struct var *vp;
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139 | struct var **vpp;
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140 |
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141 | for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
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142 | if ((vp->flags & VEXPORT) == 0) {
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143 | vpp = hashvar(ip->text);
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144 | vp->next = *vpp;
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145 | *vpp = vp;
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146 | vp->text = ip->text;
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147 | vp->flags = ip->flags;
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148 | }
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149 | }
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150 | /*
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151 | * PS1 depends on uid
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152 | */
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153 | if ((vps1.flags & VEXPORT) == 0) {
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154 | vpp = hashvar("PS1=");
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155 | vps1.next = *vpp;
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156 | *vpp = &vps1;
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157 | vps1.text = getuid() ? "PS1=$ " : "PS1=# ";
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158 | vps1.flags = VSTRFIXED|VTEXTFIXED;
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159 | }
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160 | }
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161 |
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162 | /*
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163 | * Set the value of a variable. The flags argument is ored with the
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164 | * flags of the variable. If val is NULL, the variable is unset.
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165 | */
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166 |
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167 | void
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168 | setvar(name, val, flags)
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169 | char *name, *val;
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170 | {
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171 | char *p, *q;
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172 | int len;
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173 | int namelen;
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174 | char *nameeq;
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175 | int isbad;
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176 |
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177 | isbad = 0;
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178 | p = name;
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179 | if (! is_name(*p++))
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180 | isbad = 1;
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181 | for (;;) {
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182 | if (! is_in_name(*p)) {
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183 | if (*p == '\0' || *p == '=')
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184 | break;
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185 | isbad = 1;
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186 | }
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187 | p++;
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188 | }
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189 | namelen = p - name;
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190 | if (isbad)
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191 | error("%.*s: is read only", namelen, name);
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192 | len = namelen + 2; /* 2 is space for '=' and '\0' */
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193 | if (val == NULL) {
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194 | flags |= VUNSET;
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195 | } else {
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196 | len += strlen(val);
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197 | }
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198 | p = nameeq = ckmalloc(len);
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199 | q = name;
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200 | while (--namelen >= 0)
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201 | *p++ = *q++;
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202 | *p++ = '=';
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203 | *p = '\0';
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204 | if (val)
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205 | scopy(val, p);
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206 | setvareq(nameeq, flags);
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207 | }
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208 |
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209 |
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210 |
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211 | /*
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212 | * Same as setvar except that the variable and value are passed in
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213 | * the first argument as name=value. Since the first argument will
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214 | * be actually stored in the table, it should not be a string that
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215 | * will go away.
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216 | */
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217 |
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218 | void
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219 | setvareq(s, flags)
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220 | char *s;
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221 | {
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222 | struct var *vp, **vpp;
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223 |
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224 | vpp = hashvar(s);
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225 | for (vp = *vpp ; vp ; vp = vp->next) {
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226 | if (varequal(s, vp->text)) {
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227 | if (vp->flags & VREADONLY) {
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228 | int len = strchr(s, '=') - s;
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229 | error("%.*s: is read only", len, s);
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230 | }
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231 | INTOFF;
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232 | if (vp == &vpath)
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233 | changepath(s + 5); /* 5 = strlen("PATH=") */
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234 | if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
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235 | ckfree(vp->text);
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236 | vp->flags &=~ (VTEXTFIXED|VSTACK|VUNSET);
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237 | vp->flags |= flags;
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238 | vp->text = s;
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239 | if (vp == &vmpath || (vp == &vmail && ! mpathset()))
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240 | chkmail(1);
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241 | INTON;
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242 | return;
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243 | }
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244 | }
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245 | /* not found */
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246 | vp = ckmalloc(sizeof (*vp));
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247 | vp->flags = flags;
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248 | vp->text = s;
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249 | vp->next = *vpp;
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250 | *vpp = vp;
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251 | }
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252 |
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253 |
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254 |
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255 | /*
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256 | * Process a linked list of variable assignments.
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257 | */
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258 |
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259 | void
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260 | listsetvar(list)
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261 | struct strlist *list;
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262 | {
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263 | struct strlist *lp;
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264 |
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265 | INTOFF;
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266 | for (lp = list ; lp ; lp = lp->next) {
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267 | setvareq(savestr(lp->text), 0);
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268 | }
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269 | INTON;
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270 | }
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271 |
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272 |
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273 |
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274 | /*
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275 | * Find the value of a variable. Returns NULL if not set.
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276 | */
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277 |
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278 | char *
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279 | lookupvar(name)
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280 | char *name;
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281 | {
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282 | struct var *v;
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283 |
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284 | for (v = *hashvar(name) ; v ; v = v->next) {
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285 | if (varequal(v->text, name)) {
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286 | if (v->flags & VUNSET)
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287 | return NULL;
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288 | return strchr(v->text, '=') + 1;
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289 | }
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290 | }
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291 | return NULL;
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292 | }
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293 |
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294 |
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295 |
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296 | /*
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297 | * Search the environment of a builtin command. If the second argument
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298 | * is nonzero, return the value of a variable even if it hasn't been
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299 | * exported.
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300 | */
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301 |
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302 | char *
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303 | bltinlookup(name, doall)
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304 | char *name;
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305 | {
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306 | struct strlist *sp;
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307 | struct var *v;
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308 |
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309 | for (sp = cmdenviron ; sp ; sp = sp->next) {
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310 | if (varequal(sp->text, name))
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311 | return strchr(sp->text, '=') + 1;
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312 | }
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313 | for (v = *hashvar(name) ; v ; v = v->next) {
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314 | if (varequal(v->text, name)) {
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315 | if (v->flags & VUNSET
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316 | || ! doall && (v->flags & VEXPORT) == 0)
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317 | return NULL;
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318 | return strchr(v->text, '=') + 1;
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319 | }
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320 | }
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321 | return NULL;
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322 | }
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323 |
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324 |
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325 |
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326 | /*
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327 | * Generate a list of exported variables. This routine is used to construct
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328 | * the third argument to execve when executing a program.
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329 | */
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330 |
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331 | char **
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332 | environment() {
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333 | int nenv;
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334 | struct var **vpp;
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335 | struct var *vp;
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336 | char **env, **ep;
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337 |
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338 | nenv = 0;
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339 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
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340 | for (vp = *vpp ; vp ; vp = vp->next)
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341 | if (vp->flags & VEXPORT)
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342 | nenv++;
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343 | }
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344 | ep = env = stalloc((nenv + 1) * sizeof *env);
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345 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
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346 | for (vp = *vpp ; vp ; vp = vp->next)
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347 | if (vp->flags & VEXPORT)
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348 | *ep++ = vp->text;
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349 | }
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350 | *ep = NULL;
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351 | return env;
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352 | }
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353 |
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354 |
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355 | /*
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356 | * Called when a shell procedure is invoked to clear out nonexported
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357 | * variables. It is also necessary to reallocate variables of with
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358 | * VSTACK set since these are currently allocated on the stack.
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359 | */
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360 |
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361 | #ifdef mkinit
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362 | MKINIT void shprocvar();
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363 |
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364 | SHELLPROC {
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365 | shprocvar();
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366 | }
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367 | #endif
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368 |
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369 | void
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370 | shprocvar() {
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371 | struct var **vpp;
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372 | struct var *vp, **prev;
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373 |
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374 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
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375 | for (prev = vpp ; (vp = *prev) != NULL ; ) {
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376 | if ((vp->flags & VEXPORT) == 0) {
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377 | *prev = vp->next;
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378 | if ((vp->flags & VTEXTFIXED) == 0)
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379 | ckfree(vp->text);
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380 | if ((vp->flags & VSTRFIXED) == 0)
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381 | ckfree(vp);
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382 | } else {
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383 | if (vp->flags & VSTACK) {
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384 | vp->text = savestr(vp->text);
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385 | vp->flags &=~ VSTACK;
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386 | }
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387 | prev = &vp->next;
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388 | }
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389 | }
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390 | }
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391 | initvar();
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392 | }
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393 |
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394 |
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395 |
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396 | /*
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397 | * Command to list all variables which are set. Currently this command
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398 | * is invoked from the set command when the set command is called without
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399 | * any variables.
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400 | */
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401 |
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402 | int
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403 | showvarscmd(argc, argv) char **argv; {
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404 | struct var **vpp;
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405 | struct var *vp;
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406 |
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407 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
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408 | for (vp = *vpp ; vp ; vp = vp->next) {
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409 | if ((vp->flags & VUNSET) == 0)
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410 | out1fmt("%s\n", vp->text);
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411 | }
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412 | }
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413 | return 0;
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414 | }
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415 |
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416 |
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417 |
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418 | /*
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419 | * The export and readonly commands.
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420 | */
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421 |
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422 | int
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423 | exportcmd(argc, argv) char **argv; {
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424 | struct var **vpp;
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425 | struct var *vp;
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426 | char *name;
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427 | char *p;
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428 | int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
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429 |
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430 | listsetvar(cmdenviron);
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431 | if (argc > 1) {
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432 | while ((name = *argptr++) != NULL) {
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433 | if ((p = strchr(name, '=')) != NULL) {
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434 | p++;
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435 | } else {
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436 | vpp = hashvar(name);
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437 | for (vp = *vpp ; vp ; vp = vp->next) {
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438 | if (varequal(vp->text, name)) {
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439 | vp->flags |= flag;
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440 | goto found;
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441 | }
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442 | }
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443 | }
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444 | setvar(name, p, flag);
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445 | found:;
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446 | }
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447 | } else {
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448 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
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449 | for (vp = *vpp ; vp ; vp = vp->next) {
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450 | if (vp->flags & flag) {
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451 | for (p = vp->text ; *p != '=' ; p++)
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452 | out1c(*p);
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453 | out1c('\n');
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454 | }
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455 | }
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456 | }
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457 | }
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458 | return 0;
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459 | }
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460 |
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461 |
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462 | /*
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463 | * The "local" command.
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464 | */
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465 |
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466 | localcmd(argc, argv) char **argv; {
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467 | char *name;
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468 |
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469 | if (! in_function())
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470 | error("Not in a function");
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471 | while ((name = *argptr++) != NULL) {
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472 | mklocal(name);
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473 | }
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474 | return 0;
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475 | }
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476 |
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477 |
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478 | /*
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479 | * Make a variable a local variable. When a variable is made local, it's
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480 | * value and flags are saved in a localvar structure. The saved values
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481 | * will be restored when the shell function returns. We handle the name
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482 | * "-" as a special case.
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483 | */
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484 |
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485 | void
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486 | mklocal(name)
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487 | char *name;
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488 | {
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489 | struct localvar *lvp;
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490 | struct var **vpp;
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491 | struct var *vp;
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492 |
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493 | INTOFF;
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494 | lvp = ckmalloc(sizeof (struct localvar));
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495 | if (name[0] == '-' && name[1] == '\0') {
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496 | lvp->text = ckmalloc(sizeof optval);
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497 | bcopy(optval, lvp->text, sizeof optval);
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498 | vp = NULL;
|
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499 | } else {
|
---|
500 | vpp = hashvar(name);
|
---|
501 | for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
|
---|
502 | if (vp == NULL) {
|
---|
503 | if (strchr(name, '='))
|
---|
504 | setvareq(savestr(name), VSTRFIXED);
|
---|
505 | else
|
---|
506 | setvar(name, NULL, VSTRFIXED);
|
---|
507 | vp = *vpp; /* the new variable */
|
---|
508 | lvp->text = NULL;
|
---|
509 | lvp->flags = VUNSET;
|
---|
510 | } else {
|
---|
511 | lvp->text = vp->text;
|
---|
512 | lvp->flags = vp->flags;
|
---|
513 | vp->flags |= VSTRFIXED|VTEXTFIXED;
|
---|
514 | if (strchr(name, '='))
|
---|
515 | setvareq(savestr(name), 0);
|
---|
516 | }
|
---|
517 | }
|
---|
518 | lvp->vp = vp;
|
---|
519 | lvp->next = localvars;
|
---|
520 | localvars = lvp;
|
---|
521 | INTON;
|
---|
522 | }
|
---|
523 |
|
---|
524 |
|
---|
525 | /*
|
---|
526 | * Called after a function returns.
|
---|
527 | */
|
---|
528 |
|
---|
529 | void
|
---|
530 | poplocalvars() {
|
---|
531 | struct localvar *lvp;
|
---|
532 | struct var *vp;
|
---|
533 |
|
---|
534 | while ((lvp = localvars) != NULL) {
|
---|
535 | localvars = lvp->next;
|
---|
536 | vp = lvp->vp;
|
---|
537 | if (vp == NULL) { /* $- saved */
|
---|
538 | bcopy(lvp->text, optval, sizeof optval);
|
---|
539 | ckfree(lvp->text);
|
---|
540 | } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
|
---|
541 | unsetvar(vp->text);
|
---|
542 | } else {
|
---|
543 | if ((vp->flags & VTEXTFIXED) == 0)
|
---|
544 | ckfree(vp->text);
|
---|
545 | vp->flags = lvp->flags;
|
---|
546 | vp->text = lvp->text;
|
---|
547 | }
|
---|
548 | ckfree(lvp);
|
---|
549 | }
|
---|
550 | }
|
---|
551 |
|
---|
552 |
|
---|
553 | setvarcmd(argc, argv) char **argv; {
|
---|
554 | if (argc <= 2)
|
---|
555 | return unsetcmd(argc, argv);
|
---|
556 | else if (argc == 3)
|
---|
557 | setvar(argv[1], argv[2], 0);
|
---|
558 | else
|
---|
559 | error("List assignment not implemented");
|
---|
560 | return 0;
|
---|
561 | }
|
---|
562 |
|
---|
563 |
|
---|
564 | /*
|
---|
565 | * The unset builtin command. We unset the function before we unset the
|
---|
566 | * variable to allow a function to be unset when there is a readonly variable
|
---|
567 | * with the same name.
|
---|
568 | */
|
---|
569 |
|
---|
570 | unsetcmd(argc, argv) char **argv; {
|
---|
571 | char **ap;
|
---|
572 |
|
---|
573 | for (ap = argv + 1 ; *ap ; ap++) {
|
---|
574 | unsetfunc(*ap);
|
---|
575 | unsetvar(*ap);
|
---|
576 | }
|
---|
577 | return 0;
|
---|
578 | }
|
---|
579 |
|
---|
580 |
|
---|
581 | /*
|
---|
582 | * Unset the specified variable.
|
---|
583 | */
|
---|
584 |
|
---|
585 | STATIC void
|
---|
586 | unsetvar(s)
|
---|
587 | char *s;
|
---|
588 | {
|
---|
589 | struct var **vpp;
|
---|
590 | struct var *vp;
|
---|
591 |
|
---|
592 | vpp = hashvar(s);
|
---|
593 | for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
|
---|
594 | if (varequal(vp->text, s)) {
|
---|
595 | INTOFF;
|
---|
596 | if (*(strchr(vp->text, '=') + 1) != '\0'
|
---|
597 | || vp->flags & VREADONLY) {
|
---|
598 | setvar(s, nullstr, 0);
|
---|
599 | }
|
---|
600 | vp->flags &=~ VEXPORT;
|
---|
601 | vp->flags |= VUNSET;
|
---|
602 | if ((vp->flags & VSTRFIXED) == 0) {
|
---|
603 | if ((vp->flags & VTEXTFIXED) == 0)
|
---|
604 | ckfree(vp->text);
|
---|
605 | *vpp = vp->next;
|
---|
606 | ckfree(vp);
|
---|
607 | }
|
---|
608 | INTON;
|
---|
609 | return;
|
---|
610 | }
|
---|
611 | }
|
---|
612 | }
|
---|
613 |
|
---|
614 |
|
---|
615 |
|
---|
616 | /*
|
---|
617 | * Find the appropriate entry in the hash table from the name.
|
---|
618 | */
|
---|
619 |
|
---|
620 | STATIC struct var **
|
---|
621 | hashvar(p)
|
---|
622 | register char *p;
|
---|
623 | {
|
---|
624 | unsigned int hashval;
|
---|
625 |
|
---|
626 | hashval = *p << 4;
|
---|
627 | while (*p && *p != '=')
|
---|
628 | hashval += *p++;
|
---|
629 | return &vartab[hashval % VTABSIZE];
|
---|
630 | }
|
---|
631 |
|
---|
632 |
|
---|
633 |
|
---|
634 | /*
|
---|
635 | * Returns true if the two strings specify the same varable. The first
|
---|
636 | * variable name is terminated by '='; the second may be terminated by
|
---|
637 | * either '=' or '\0'.
|
---|
638 | */
|
---|
639 |
|
---|
640 | STATIC int
|
---|
641 | varequal(p, q)
|
---|
642 | register char *p, *q;
|
---|
643 | {
|
---|
644 | while (*p == *q++) {
|
---|
645 | if (*p++ == '=')
|
---|
646 | return 1;
|
---|
647 | }
|
---|
648 | if (*p == '=' && *(q - 1) == '\0')
|
---|
649 | return 1;
|
---|
650 | return 0;
|
---|
651 | }
|
---|