How can I check whether user input contains digits in C++?
I'm reading the user's choice into a std::string and need to validate it before converting it with std::stoi. The input should be a number, such as 1, 2,…
regular expressions
Do I need to memorize regular expressions to become a good JavaScript programmer?
Regular expressions look extremely complicated to me, almost like random keyboard symbols. Some people say programmers should memorize the syntax, but I'm not sure that's realistic. Do I…
Do I need to memorize regular expressions to become a good JavaScript programmer?
Regular expressions initially look like a confusing pile of symbols, and I've seen people suggest that programmers should memorize them. For JavaScript, do I need to memorize complete…
How can I check whether user input is a digit in C++?
I'm reading input into a std::string and need to determine whether it contains a digit or another character. The input should represent a playlist choice from 1 through…
What does | mean in this grep command?
I'm looking at a shell script that runs an nmap scan and saves matching lines to a variable: RESULT=$(nmap -iL $(HOSTS) --open | grep "Nmap scan report|tcp open")…
What does `|` mean in this grep command?
I'm looking at a shell script that runs an nmap scan and stores selected lines in a variable: RESULT=$(nmap -iL $(HOSTS) --open | grep "Nmap scan report|tcp open")…
How can I remove the leading “Modeline” text with sed?
I'm generating an X11 modeline in Bash with gtf and trying to process its output. The line looks like this: Modeline "1440x800_60.00" 93.80 1440 1512 1664 1888 800…
Where can I test Bash POSIX ERE patterns interactively?
I'm looking for an online regex playground similar to Regex101, but specifically for the POSIX Extended Regular Expressions used by Bash's =~ operator. Ideally, it should let me…
How Do I Keep Straight the Differences Between Globbing and Regular Expressions?
Hey everyone, I'm looking for some advice on how to remember and differentiate between globbing, pattern matching, and regular expressions. I find that every time I need to…