Below is the bash script
the value of b returned by the script is 0 or 1.
b=`tail -l /apps_data_01/mc_migs/inbound/logs/fp.syslog | awk c=$7} {print $c}
if ((!"$b" eq "0"));then
fi
if (($b==0));then
fi
Error:
((: ! eq 0: syntax error in expression (error token is "0")
((: ==0: syntax error: operand expected (error token is "==0")
Correct syntax is the following:
b=0
if [[ ! "$b" == "0" ]];then
echo "Not EQ"
fi
if [[ $b == 0 ]];then
echo "EQ"
fi
Please note [[ and spaces.
Using the [[ ... ]] test construct, rather than [ ... ] can prevent many logic errors in scripts. For example, the &&, ||, <, and > operators work within a [[ ]] test, despite giving an error within a [ ] construct. its a good practice to use them
[ ] is the original test command, which is portable to all POSIX shells, but has nasty syntactic oddities. [[ ]] is a bash extension, with much cleaner syntax and some additional capabilities (like regular expression matching with =~). (( )) is another bash extension that does arithmetic only, not string comparisons (but can do more math, like if (( x*2 >= y+5 )); then...).bash uses [] to enclose the condition for an if statement. Also you need spaces before and after the == operator. See http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_07_01.html for more details about if syntax in bash scripts.
Note that you can use an else to avoid duplicating the comparison.
(( )) is appropriate for strictly numeric comparisons, but in this case it's acting like $b is blank, making for invalid numeric expressions. If some "numbers" might not actually be numbers (and you don't need greater/less comparisons, just equal/not equal), [[ ]] or [ ] is safer.
[ does not "enclose" the condition for an if statement. if simply takes any list of commands as the condition, and [ is just one command (an unfortunate alias of test) that is commonly used.