32,818 reputation
44687
bio website blog.denniswilliamson.us
location United States
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visits member for 5 years, 4 months
seen 30 mins ago

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I'm a Unix/Linux sysadmin/programmer

Devotion to Duty
Devotion to Duty
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Aug
21
awarded  Popular Question
Aug
20
awarded  Nice Answer
Aug
5
comment How to determine if a bash variable is empty?
@antonio: Thanks, that's a relatively recently added feature and I checked an earlier version. ksh also supports it, by the way.
Aug
5
revised How to determine if a bash variable is empty?
removed reference to zsh
Aug
5
comment How to determine if a bash variable is empty?
@antonio: I don't know what -v is supposed to be, Bash doesn't have such a test. It appears that you are correct about zsh. While it supports the double bracket syntax, it doesn't appear to support an implied test. I'll edit my answer.
Aug
1
awarded  Nice Answer
Jul
26
comment How to tell GNU screen to run .bash_profile in each new window?
@THESorcerer: On my system, screen sources ~/.bashrc without the shell command shown in the other answer.
Jul
18
awarded  Nice Answer
Jul
10
comment How to create a UUID in bash?
@Rob: To answer your original question, it's for drive labels.
Jul
7
comment What's the difference between authorized_keys and authorized_keys2?
@javadba: CentOS is in the same boat as Red Hat.
Jul
5
awarded  Nice Answer
Jul
2
awarded  Curious
Jun
11
answered Year Month day from file name in shell script
Jun
2
comment Shell script only executes partially when run with CRON
Please see the canonical Why is my crontab not working, and how can I troubleshoot it?.
Jun
2
comment Replacing LineFeed \x0a with SED
Another way with sed: sed -n 'H;${g;s/\n//g;p}'. In this version which saves the lines in hold space, sed does the looping for free without an explicit loop. One thing to note about using tr in this way: the final newline is also removed.
Jun
2
comment Bash if statement equal output from last command
Backticks are deprecated in favor of $().
May
30
awarded  Nice Answer
May
26
answered How to split a file and compress directly?
May
24
awarded  sed
May
22
comment How to create a UUID in bash?
I added a comment to the code at the github link showing a version using case to eliminate the if statements as well as the inner for statement. It makes the code much neater. Note that both B%15 should be B%16 and B%255 should be B%256.