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8
votes
2answers
810 views

How can I use $var in a shell brace expansion of a sequence?

I want to use $var in a shell brace expansion with a range, in bash. Simply putting {$var1..$var2} doesn't work, so I went "lateral"... The following works, but it's a bit kludgey. # remove the ...
29
votes
6answers
3k views

When do you use brace expansion?

I understand what brace expansion is, but I don't know how best to use it. When do you use it? Please teach me some convenient and remarkable examples if you have your own tip.
15
votes
6answers
11k views

How to create a sequence with leading zeroes using brace expansion

When I use the following, I get a result as expected: $ echo {8..10} 8 9 10 How can I use this brace expansion in an easy way, to get the following output? $ echo {8..10} 08 09 10 I now that ...
5
votes
2answers
218 views

How can I force bash to deallocate a brace expanded variable without name?

For benchmarking, I ran the command: for i in {1..100000000}; do echo "$i" line >> file done Bash expanded the braces and stored the list 1 2 3 4 5 6 ... 100000000 in memory. I thought ...
4
votes
1answer
193 views

`seq` and bash brace expansion failing

IINM my system is failing when bashing for i in {0..10000000}; # Seven zeroes. do false; done # `bash` exited and its `tmux` pane/window was closed. or for i in $(seq 0 10000000); # ...
3
votes
2answers
105 views

Can I use variables inside {} expansion without `eval`?

Can I use variables inside {} expansion without appealing to eval? If so, how? This doesn't work: $ touch 1.foo 1.bar $ ls 1.{foo,bar} 1.bar 1.foo $ extensions=foo,bar $ ls 1.{$extensions} ls: ...
2
votes
1answer
127 views

cp : short way of copying [closed]

I don't remember exactly but there was either cp or mv command which I was able to do something like this with: cp file{.cpp, .cpp.org} Which would copy file.cpp and make a copy named file.cpp.org. ...
4
votes
2answers
99 views

Brace compression

I love brace expansion (e.g. rm file.{0..5}). I find it a lot easier to read than the expanded version. Is there a quick and easy way of doing the opposite? For example given the input ...
2
votes
2answers
105 views

How to combine arithmetic expansion and brace expansion? [duplicate]

Can peoples combine arithmetic expansion and brace expansion? $ for i in {$((1 + 1))..5}; do echo $i; done; {2..5} $ echo "bash laughs at me"
1
vote
3answers
350 views

Why brace expansion not supported?

Do I have to do any configuration to start brace expansion? When I run mkdir {1..10}, it just creates a dir naming {1..10}.
1
vote
2answers
299 views

brace expansion other commands besides mkdir?

Found this nifty lifehacking gem to create multiple directories: http://unix.stackexchange.com/a/640/7768 I was wondering if there are other commands support brace expansion?