## page was renamed from GNUCoreUtils

<<TableOfContents>>

== Set operations on lines of a file ==

{{{#!highlight sh numbers=off
# Union of unsorted files, items in either file1 or file2
sort file1 file2 | uniq
# Intersection of unsorted files, items in both file1 and file2
sort file1 file2 | uniq -d
# Difference of unsorted files, items in file2 not in file1
sort file1 file1 file2 | uniq -u
# Symmetric Difference of unsorted files, items in file1 or file2 but not both
sort file1 file2 | uniq -u
}}}

== Backup ==

{{{#!highlight sh numbers=off
# CAVEAT: apparently does not backup setuid bits?
tar cvpf backup.tar \
--exclude=/proc \
--exclude=/lost+found \
--exclude=/backup.tar \
--exclude=/mnt \
--exclude=/sys \
--exclude=/dev/pts \
/
}}}

== Unit conversion ==

{{{#!highlight sh numbers=off
units -t '100m/9.58s' 'miles/hour'
units -t '500GB' 'GiB'
units -t '1 googol'
}}}

== Dates ==

=== What time is it elsewhere? ===

{{{#!highlight sh numbers=off
TZ='America/Los_Angeles' date
TZ='America/Denver' date
TZ='America/New_York' date
TZ='UTC' date
}}}

Check /usr/share/zoneinfo/ to find values for $TZ.

=== Convert UNIX epoch seconds to date ===

{{{#!highlight sh numbers=off
date --date='@2147483647'
}}}

=== Exit a script unless it's the last day of the month ===

{{{#!highlight sh numbers=off
[ $(date -d "tomorrow" +%d) = "01" ] || exit
}}}

=== Calendar for particular month and year ===

{{{#!highlight sh numbers=off
cal 9 1752
}}}
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CategoryCheatSheet