backticks

问题 For the command: /usr/bin/sh -c "ls 1`" (a backquote after 1). How to make it run successfully? Adding a backslash before "`" does not work. ` is a special char as we know, and I tried surrounding it with single quote too (/usr/bin/sh -c "ls 1'`'"), but that doesn't work either. The error always are: % /usr/bin/sh -c "ls 1\`" Unmatched ` 回答1: You need to escape the backtick, but also escape the backslash: $ touch 1\` $ /bin/sh -c "ls 1\\\`" 1` The reason you have to escape it "twice" is

问题 Previously my all queries were running fine in CI version 2.0 but when I upgraded to 2.0.3 some of my SELECT queries were broken. CI is adding backticks (``) automatically, but in older version its running as it is. CI user manual have instructed to add second parameter in db->select as FALSE but still it's not working. Code is as following: class Company_model extends MY_Model { ---------------- $this->db->select(' count('.$fieldname. ') as num_stations'); $this->db->select(" CONCAT_WS(',',

问题 In the codeigniter manual writes the following. $this->db->select() accepts an optional second parameter. If you set it to FALSE, CodeIgniter will not try to protect your field or table names with backticks. This is useful if you need a compound select statement. $this->db->select('(SELECT SUM(payments.amount) FROM payments WHERE payments.invoice_id=4) AS amount_paid', FALSE); $query = $this->db->get('mytable'); ... And I have the following code from one of CI applications. $this->db->select(

问题 After reading a couple of answers and comments on some SQL questions here, and also hearing that a friend of mine works at a place which has a policy which bans them, I'm wondering if there's anything wrong with using backticks around field names in MySQL. That is: SELECT `id`, `name`, `anotherfield` ... -- vs -- SELECT id, name, anotherfield ... 回答1: Using backticks permits you to use alternative characters. In query writing it's not such a problem, but if one assumes you can just use

问题 This question already has answers here : Can PHP PDO Statements accept the table or column name as parameter? (7 answers) Closed 4 years ago . I have a table with hyphens in the name, and I can't change the table name so I thought backticks would help. Unfortunally for me it failed, some googling did'nt give me any answers. How can I solve this? ex: $stmt = $this->_dbh->prepare( 'UPDATE `:table` SET status = NOT status WHERE id=:id;'); $stmt->bindParam(':table',$this->_settings['table'], PDO:

问题 In my project I want to write a script to check if every device in my network is online/reachable. I have a method called pingtest and it works for now.. def pingtest(destination) system("ping -n 2 #{destination}") if $? == 0 #checking status of the backtick puts "\n Ping was successful!" else close("Device is unreachable. Check the config.txt for the correct IPs.") #close() is just print & exit.. end end Now I wanted to ping via a ssh session with an other device in my network: #------------

问题 I am trying to test a specific server is up and running on a certain port so I am using $result = `echo exit | telnet 127.0.0.1 9443`; print $result; Here I am using localhost for privacy issues The expected behavior is that it should print "...Could not open connection to the host, on port 9443: Connect failed", this way I know that the server is not running. but it prints an empty string Any help on this 回答1: The failure message is printed to STDERR , while backticks return only what goes

问题 I have a php code that will create a table to mysql database using a csv file. However, some column headers are not being read by mysql. The only time that mysql will read the query is when I add backticks(`) . Can you help me on where to put backticks in my query? :( Here's my code: $file = 'C:\Users\user\Desktop\Sample CSV Files\672VER.csv'; $table = '`672ver`'; // get structure from csv and insert db ini_set('auto_detect_line_endings',TRUE); $handle = fopen($file,'r'); // first row,

问题 I have the following backtick on my list's names. Prior lists did not have this backtick. $`1KG_1_14106394` [1] "PRDM2" $`1KG_20_16729654` [1] "OTOR" I found out that this is a 'ASCII grave accent' and read the R page on encoding types. However what to do about it ? I am not clear if this will effect some functions (such as matching on list names) or is it OK leave it as is ? Encoding help page: https://stat.ethz.ch/R-manual/R-devel/library/base/html/Encoding.html Thanks! 回答1: My

问题 hindent changed my code to: do download i inputFile onException (callProcess (List.head args) (List.tail args)) (removeFileIfExists name) `finally` removeFileIfExists inputFile I can't determine if the finally applies to the rest of the do block, or just the state beginning onException . According to this, If you see something unexpected in a list, like where, insert a closing brace before instead of a semicolon. I'm unsure if that rule is applying here. Does the `finally` apply to the rest