• variable=value -> sets “value” to “variable”
  • ${variable} -> use value of “variable” – braces are optional if variable is separated from other following text but are required for array
  • ${variable:-value} -> substitution for not set variable without change in variable = use variable if set, otherwise use value but do nothing with variable
  • ${variable:=value} -> substitution for not set variable WITH change in variable = use variable if set, otherwise use value and SET it also into variable
  • ${#variable} -> use the length of variable
  • ${variable:position} -> substring from variable, starting at “position” (0=start position) till the end of string
  • ${variable:position:length} -> the same as previous, with specified length of substring
  • ${variable/pattern} -> use value from variable and delete first match of “pattern”
  • ${variable/pattern/replacement} -> use value from variable and first match of “pattern” replace with “replacement”
  • ${variable//pattern/replacement} -> use value from variable and all matches of “pattern” replace with “replacement”
  • ${!variable} -> use value of variable as name of other variable from which variable should be really used