bash - Shell equality operators (=, ==, -eq) - Stack Overflow If not quoted, it is a pattern match! (From the Bash man page: "Any part of the pattern may be quoted to force it to be matched as a string ") Here in Bash, the two statements yielding "yes" are pattern matching, other three are string equality:
shell - Bash regex =~ operator - Stack Overflow The [[ ]] is treated specially by bash; consider that an augmented version of [ ] construct: [ ] is actually a shell built-in command, which, can actually be implemented as an external command Look at your usr bin, there is most likely a program called "[" there! Strictly speaking, [ ] is not part of bash syntax
linux - What does $@ mean in a shell script? - Stack Overflow (View Special parameters - Bash Manual) For instance, if you call someScript sh foo bar then $@ will be equal to foo bar If you do: someScript sh foo bar and then inside someScript sh reference: umbrella_corp_options "$@"
How do AND and OR operators work in Bash? - Stack Overflow In bash, and || have equal precendence and associate to the left See Section 3 2 3 in the manual for details So, your example is parsed as $ (echo this || echo that) echo other And thus only the left-hand side of the or runs, since that succeeds the right-hand side doesn't need to run
An and operator for an if statement in Bash - Stack Overflow Modern shells such as Bash and Zsh have inherited this construct from Ksh, but it is not part of the POSIX specification If you're in an environment where you have to be strictly POSIX compliant, stay away from it; otherwise, it's basically down to personal preference Note that the arithmetic substitution expression $((
Whats the difference between lt; lt;, lt; lt; lt; and lt; lt; in bash? In bash these are implemented via temp files, usually in the form tmp sh-thd <random string>, while in dash they are implemented as anonymous pipes This can be observed via tracing system calls with strace command Replace bash with sh to see how bin sh performs this redirection $ strace -e open,dup2,pipe,write -f bash -c 'cat <<EOF > test
How to compare strings in Bash - Stack Overflow Bash always seemed backward with numeric evaluations using an operator consisting of a string (-eq) and string comparisons using a numeric operator "==" or "=" just you mess you up If you ask me I'd say the problem is the distro swapping out bash That is just my opinion, but this is my fix ln bin bash bin sh -sf
bash - Precedence of the shell logical operators , || - Unix Linux . . . This is not the case with Bash, however, in which both operators have the same precedence, which is why Bash parses your expression using the left-associativity rule Thanks to Kevin's comment for bringing this up There might also be cases where all 3 expressions are evaluated