coreutils: Set operations
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1 8.3.6 Union, Intersection and Difference of files
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1 Combine ‘sort’, ‘uniq’ and ‘join’ to perform the equivalent of set
1 operations on files:
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1 Command outcome
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1 ‘sort -u file1 file2’ Union of unsorted files
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1 ‘sort file1 file2 | uniq -d’ Intersection of unsorted files
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1 ‘sort file1 file1 file2 | uniq’ Difference of unsorted files
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1 ‘sort file1 file2 | uniq -u’ Symmetric Difference of unsorted
1 files
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1 ‘join -t'' -a1 -a2 file1 file2’ Union of sorted files
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1 ‘join -t'' file1 file2’ Intersection of sorted files
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1 ‘join -t'' -v2 file1 file2’ Difference of sorted files
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1 ‘join -t'' -v1 -v2 file1 file2’ Symmetric Difference of sorted
1 files
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1 All examples above operate on entire lines and not on specific
1 fields: ‘sort’ without ‘-k’ and ‘join -t''’ both consider entire lines
1 as the key.
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