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I'm used to csh, so this is kinda irritating having to use bash. What is wrong with this code?
if[$time > 0300] && [$time < 0900]
then
$mod=2
else
$mod=0
fi
217
A variable in bash is created by assigning a value to its reference. Although the built-in declare statement does not need to be used to explicitly declare a variable in bash, the command is often employed for more advanced variable management tasks.
$1 means an input argument and -z means non-defined or empty. You're testing whether an input argument to the script was defined when running the script. Follow this answer to receive notifications.
A null string in Bash can be declared by equalizing a variable to “”. Then we have an “if” statement followed by the “-n” flag, which returns true if a string is not null. We have used this flag to test our string “name,” which is null.
This will work: x = $(if [ 2 = 2 ]; then echo equal; else echo "not equal; fi) .
By standard it should be
if [ "$time" -gt 300 ] && [ "$time" -lt 900 ]
then
mod=2
else
mod=0
fi
In normal shell scripts you use [ and ] to test values. There are no arithmetic-like comparison operators like > and < in [ ], only -lt, -le, -gt, -ge, -eq and -ne.
When you're in bash, [[ ]] is preferred since variables are not subject to splitting and pathname expansion. You also don't need to expand your variables with $ for arithmetic comparisons.
if [[ time -gt 300 && time -lt 900 ]]
then
mod=2
else
mod=0
fi
Also, using (( )) for arithmetic comparisons could be best for your preference:
if (( time > 300 && time < 900 ))
then
mod=2
else
mod=0
fi
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