The eval command in Bash and its typical uses - Stack Overflow The eval statement tells the shell to take eval’s arguments as commands and run them through the command-line It is useful in a situation like below: In your script if you are defining a command into a variable and later on you want to use that command then you should use eval :
Why is using the JavaScript eval function a bad idea? eval'd code executes slower (no opportunity to compile cache eval'd code) Edit: As @Jeff Walden points out in comments, #3 is less true today than it was in 2008 However, while some caching of compiled scripts may happen this will only be limited to scripts that are eval'd repeated with no modification
Is there ever a good reason to use eval ()? - Stack Overflow When creating testing code segments eval is PERFECT! Just build a basic scaffolding webpage with textareas and an eval button Put code into a textarea then press eval button It's faster than switching back and forth between your text editor and browser eval edit code press eval button switching method
Exploiting JavaScripts eval () method - Stack Overflow The danger of eval() is that an attacker may be able to manipulate data that is eventually run through eval() in other ways If the eval()'d string comes from an HTTP connection, the attacker may perform a MITM attack and modify the string If the string comes from external storage, the attacker may have manipulated the data in that storage
What is the eval command in bash? - Unix Linux Stack Exchange At step 6 eval causes the processed line to be sent back to step 1 It is the only condition under which the execution sequence goes back That is why I say: With eval an input line is parsed twice Effects of parsing twice The first And most important effect to understand
What does the eval() function do in Python? - Stack Overflow The reason for using eval is that it evaluates an expression which is passed as a string So for example if you pass "2*3" to eval it will return 6 The documentation for eval is here which is always a good place to start Breaking down the line which is giving you trouble: result = eval(str(number1)+oper+str(number2))