exec

问题 Attempt to generalize my questions... I want to execute a stored procedure for each result returned by a SELECT statement. Mentally I want to try something like EXEC myStoredProc (SELECT id FROM sometable WHERE cond = @param) More details related to my specific case... I have a SaaS application. I would like to delete a tenant from the system. Before I can delete the tenant I must delete all records in the database associated with that tenant. Tenants own items such as Forms which contain

问题 I was trying to execute this command echo exec("top"); and echo exec("/usr/bin/top"); neither works (returns blank output) does anybody know why? 回答1: Because top is an interactive program that is meant to be run on a terminal, not be executed from a script. You are probably want to run the 'ps' command with arguments which will sort output by cpu utilization. http://www.devdaily.com/linux/unix-linux-process-memory-sort-ps-command-cpu 回答2: It probably works, but exec() doesn't return anything

问题 I'm coding a web interface to a horrible piece of propitiatory software our company uses. The software has no real UI and requires us giving putty access to our system for our clients to even pull data. My web interface has to run an exec(); function and it has to pass a few variables the user inputs. $command = "report-call '$type' '$study' '$server' '$tag' '$specopt1' '$specopt2' '$specopt3' '$specopt4'"; $last_line = exec($command, $output, $returnvalue); Now I assume I might be able to

问题 I know that cd is a shell built-in ,and I can run it by using system() . But is that possible to run the cd command by the exec() family, like execvp() ? Edit: And I just noticed that system("cd") is also meaningless。Thanks for the help of everyone. 回答1: exec loads an executable file and replaces the current program image with it. As you rightly noted, cd is not an executable file, but rather a shell builtin. So the executable that you want to run is the shell itself. This is of course what

问题 I know that cd is a shell built-in ,and I can run it by using system() . But is that possible to run the cd command by the exec() family, like execvp() ? Edit: And I just noticed that system("cd") is also meaningless。Thanks for the help of everyone. 回答1: exec loads an executable file and replaces the current program image with it. As you rightly noted, cd is not an executable file, but rather a shell builtin. So the executable that you want to run is the shell itself. This is of course what

问题 I'm writing a PHP script to be used to check for network connections with Linux shell command ping calling it with PHP's exec() : <?php // Bad IP domain for testing. $domain_bad = "lksjdflksjdf.com"; $ip_address = $domain_bad; exec("ping -c 1 $domain_bad", $output, $return_var); var_dump($return_var); echo "return_var is: $return_var" . "\n"; var_dump($output); exit; ?> I'm not getting the output for the error message from ping in $output which is what I'm expecting: $ php try.php ping:

问题 I have the following program, when I run the program, I feel really confused that why my program didn't excute int num=i; printf("it is No.%d !",num); printf("hello , I will excute execvp!"); My program basically create 6 child processes to excute executionbode() function, and then use execvp to overload original program. However, everytime when I run the program, the string "hello, I will execute execvp" never shows up! Also I think those three sentences above also didn't execute in the

问题 I'm designing a server that will initialize by fork / exec 'ing four "managers" (themselves server processes) and will then accept connections from clients, fork / exec 'ing "slaves" to communicate with the clients. During their lifetimes, the slaves will establish connections with the managers and send them work requests. My question is about starting up the managers. Each one may take some time to initialize (minutes) and I don't want the master server to proceed to accept clients until

问题 as the title already says, I want to execute a linux comand with a very low priority so as to not disturb my app and keep it running smooth. I currently use: Runtime.getRuntime().exec Is there another way to achieve this with setting the priority ? 回答1: You can change the process priority on rooted devices with renice provided by the Busybox binary if you know the PID of the process you want to give less priority to. Just run the command using the exec function of Runtime just like you are.

问题 This question already has answers here : Safely evaluate simple string equation (2 answers) Evaluating a mathematical expression in a string (11 answers) Closed 2 years ago . I have sting input like: 12 == 21 (10 != 12) or (15 == 13) True and (10 == 10) And i need to return boolean value of this input. Can i convert it using exec() or bool() ? I don't want to write big method to solve it . 来源： https://stackoverflow.com/questions/53675559/how-to-convert-string-to-boolean-logic