Useful Oneliners

Useful Oneliners

# delete each file from stdin delimited by space or newline
xargs -n1 rm

# delete each file found using find (ex w/ .ds_store)
find . -name .DS_STORE | xargs -n1 rm

# for each url in urls run curl, grep some other url and then download each
# of these urls
cat urls | xargs -n1 -I{} sh -c "curl -s {} | grep $OTHERURL" | xargs -n1 wget

# replace one or more numbers with an underscore, good for aggregating when
# only thing changing is numbers
sed -s 's/[0-9]\+/_/'

# same thing but with perl regexes which are far better
perl -pe ‘s/[0-9]+/_/g’

# set a watch every 2 seconds to tail last 20 lines of every file matching
# /mnt/log/logs* and aggregate and sort them to see top 10
watch tail "-f -n 20 /mnt/log/logs* | sed -s 's/[0-9]\+/_/' | sort | uniq -c | sort -n | tail -n 10"

# nice ps format
ps -o user,group,pid,pgid,comm,args -u jwong

# kill process group
kill -- -$PGID

# for stuborn groups
kill -9 -- -$PGID

# echo without newline
echo -n "something"