1 | # |
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2 | # An almost ksh-compatible `autoload'. A function declared as `autoload' will |
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3 | # be read in from a file the same name as the function found by searching the |
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4 | # $FPATH (which works the same as $PATH), then that definition will be run. |
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5 | # |
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6 | # To do this without source support, we define a dummy function that, when |
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7 | # executed, will load the file (thereby re-defining the function), then |
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8 | # execute that newly-redefined function with the original arguments. |
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9 | # |
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10 | # It's not identical to ksh because ksh apparently does lazy evaluation |
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11 | # and looks for the file to load from only when the function is referenced. |
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12 | # This one requires that the file exist when the function is declared as |
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13 | # `autoload'. |
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14 | # |
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15 | # usage: autoload [-pu] [func ...] |
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16 | # |
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17 | # options: |
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18 | # -p print in a format that can be reused as input |
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19 | # -u unset each function and remove it from the autoload list |
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20 | # |
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21 | # The first cut of this was by Bill Trost, trost@reed.edu |
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22 | # |
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23 | # Chet Ramey |
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24 | # chet@ins.CWRU.Edu |
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25 | |
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26 | unset _AUTOLOADS |
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27 | _aindex=0 |
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28 | |
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29 | # |
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30 | # Declare a function ($1) to be autoloaded from a file ($2) when it is first |
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31 | # called. This defines a `temporary' function that will `.' the file |
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32 | # containg the real function definition, then execute that new definition with |
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33 | # the arguments given to this `fake' function. The autoload function defined |
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34 | # by the file and the file itself *must* be named identically. |
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35 | # |
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36 | |
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37 | _aload() |
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38 | { |
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39 | eval $1 '() { . '$2' ; '$1' "$@" ; return $? ; }' |
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40 | _autoload_addlist "$1" |
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41 | } |
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42 | |
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43 | _autoload_addlist() |
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44 | { |
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45 | local i=0 |
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46 | |
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47 | while (( i < $_aindex )); do |
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48 | case "${_AUTOLOADS[i]}" in |
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49 | "$1") return 1 ;; |
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50 | esac |
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51 | (( i += 1 )) |
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52 | done |
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53 | _AUTOLOADS[_aindex]="$1" |
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54 | (( _aindex += 1 )) |
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55 | return 0 |
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56 | } |
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57 | |
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58 | _autoload_dump() |
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59 | { |
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60 | local func |
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61 | |
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62 | for func in ${_AUTOLOADS[@]}; do |
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63 | [ -n "$1" ] && echo -n "autoload " |
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64 | echo "$func" |
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65 | done |
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66 | } |
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67 | |
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68 | # Remove $1 from the list of autoloaded functions |
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69 | _autoload_remove_one() |
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70 | { |
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71 | local i=0 nnl=0 |
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72 | local -a nlist |
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73 | |
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74 | while (( i < _aindex )); do |
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75 | case "${_AUTOLOADS[i]}" in |
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76 | "$1") ;; |
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77 | *) nlist[nnl]="${_AUTOLOADS[i]}" ; (( nnl += 1 ));; |
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78 | esac |
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79 | (( i += 1 )) |
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80 | done |
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81 | unset _AUTOLOADS _aindex |
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82 | eval _AUTOLOADS=( ${nlist[@]} ) |
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83 | _aindex=$nnl |
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84 | } |
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85 | |
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86 | # Remove all function arguments from the list of autoloaded functions |
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87 | _autoload_remove() |
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88 | { |
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89 | local func i es=0 |
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90 | |
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91 | # first unset the autoloaded functions |
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92 | for func; do |
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93 | i=0 |
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94 | while (( i < _aindex )); do |
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95 | case "${_AUTOLOADS[i]}" in |
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96 | "$func") unset -f $func ; break ;; |
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97 | esac |
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98 | (( i += 1 )) |
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99 | done |
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100 | if (( i == _aindex )); then |
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101 | echo "autoload: $func: not an autoloaded function" >&2 |
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102 | es=1 |
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103 | fi |
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104 | done |
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105 | |
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106 | # then rebuild the list of autoloaded functions |
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107 | for func ; do |
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108 | _autoload_remove_one "$func" |
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109 | done |
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110 | |
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111 | return $es |
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112 | } |
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113 | |
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114 | # |
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115 | # Search $FPATH for a file the same name as the function given as $1, and |
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116 | # autoload the function from that file. There is no default $FPATH. |
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117 | # |
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118 | |
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119 | autoload() |
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120 | { |
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121 | local -a fp |
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122 | local _autoload_unset nfp i |
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123 | |
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124 | if (( $# == 0 )) ; then |
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125 | _autoload_dump |
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126 | return 0 |
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127 | fi |
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128 | |
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129 | OPTIND=1 |
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130 | while getopts pu opt |
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131 | do |
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132 | case "$opt" in |
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133 | p) _autoload_dump printable; return 0;; |
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134 | u) _autoload_unset=y ;; |
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135 | *) echo "autoload: usage: autoload [-pu] [function ...]" >&2 |
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136 | return 1 ;; |
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137 | esac |
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138 | done |
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139 | |
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140 | shift $(( $OPTIND - 1 )) |
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141 | |
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142 | if [ -n "$_autoload_unset" ]; then |
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143 | _autoload_remove "$@" |
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144 | return $? |
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145 | fi |
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146 | |
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147 | # |
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148 | # If there is no $FPATH, there is no work to be done |
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149 | # |
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150 | |
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151 | if [ -z "$FPATH" ] ; then |
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152 | echo "autoload: FPATH not set or null" >&2 |
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153 | return 1 |
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154 | fi |
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155 | |
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156 | # |
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157 | # This treats FPATH exactly like PATH: a null field anywhere in the |
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158 | # FPATH is treated the same as the current directory. |
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159 | # |
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160 | # This turns $FPATH into an array, substituting `.' for `' |
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161 | # |
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162 | eval fp=( $( |
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163 | IFS=':' |
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164 | set -- ${FPATH} |
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165 | for p in "$@" ; do echo -n "${p:-.} "; done |
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166 | ) |
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167 | ) |
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168 | |
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169 | nfp=${#fp[@]} |
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170 | |
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171 | for FUNC ; do |
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172 | i=0; |
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173 | while (( i < nfp )) ; do |
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174 | if [ -f ${fp[i]}/$FUNC ] ; then |
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175 | break # found it! |
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176 | fi |
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177 | (( i += 1 )) |
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178 | done |
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179 | |
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180 | if (( i == nfp )) ; then |
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181 | echo "autoload: $FUNC: autoload function not found" >&2 |
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182 | es=1 |
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183 | continue |
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184 | fi |
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185 | |
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186 | # echo auto-loading $FUNC from ${fp[i]}/$FUNC |
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187 | _aload $FUNC ${fp[i]}/$FUNC |
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188 | es=0 |
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189 | done |
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190 | |
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191 | return $es |
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192 | } |
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