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Question
In linux, how do you guard against the default risky shell behavior of treating non-existing variables as empty values (e.g. if you try to reference undefined var TEXT, by $TEXT in script, value is empty string instead of causing explicit error, how do you get shell to spit out explicit error)?
Answer

set -u

^^ use the set built-in command, at top of script.

^^^ note the u stands for unset (i.e. you are enabling guarding against unset variables)


Question
In linux, how do you guard against the default risky shell behavior of treating non-existing variables as empty values (e.g. if you try to reference undefined var TEXT, by $TEXT in script, value is empty string instead of causing explicit error, how do you get shell to spit out explicit error)?
Answer
?

Question
In linux, how do you guard against the default risky shell behavior of treating non-existing variables as empty values (e.g. if you try to reference undefined var TEXT, by $TEXT in script, value is empty string instead of causing explicit error, how do you get shell to spit out explicit error)?
Answer

set -u

^^ use the set built-in command, at top of script.

^^^ note the u stands for unset (i.e. you are enabling guarding against unset variables)

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20. Advanced Shell Scripting
ur shell. This option is enabled by default. set -n Read commands without executing them. This command is useful for syntax checking. set -o posix Comply exactly with the POSIX 1003.2 standard. <span>set -u Report an error when trying to reference a variable that is unset. Usually bash just fills in an empty string. set -v Print each line of script as it is executed. set -x Display each co

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