1LOOK(1) User Commands LOOK(1)
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6 look - display lines beginning with a given string
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9 look [options] string [file]
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12 The look utility displays any lines in file which contain string. As
13 look performs a binary search, the lines in file must be sorted (where
14 sort(1) was given the same options -d and/or -f that look is invoked
15 with).
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17 If file is not specified, the file /usr/share/dict/words is used, only
18 alphanumeric characters are compared and the case of alphabetic charac‐
19 ters is ignored.
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22 -a, --alternative
23 Use the alternative dictionary file.
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25 -d, --alphanum
26 Use normal dictionary character set and order, i.e., only blanks
27 and alphanumeric characters are compared. This is on by default
28 if no file is specified.
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30 Note that blanks have been added to dictionary character set for
31 compatibility with sort -d command since version 2.28.
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33 -f, --ignore-case
34 Ignore the case of alphabetic characters. This is on by default
35 if no file is specified.
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37 -t, --terminate character
38 Specify a string termination character, i.e., only the charac‐
39 ters in string up to and including the first occurrence of char‐
40 acter are compared.
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42 -V, --version
43 Display version information and exit.
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45 -h, --help
46 Display help text and exit.
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48 The look utility exits 0 if one or more lines were found and displayed,
49 1 if no lines were found, and >1 if an error occurred.
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52 WORDLIST
53 Path to a dictionary file. The environment variable has greater
54 priority than the dictionary path defined in FILES segment.
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57 /usr/share/dict/words
58 the dictionary
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60 /usr/share/dict/web2
61 the alternative dictionary
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64 The look utility appeared in Version 7 AT&T Unix.
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67 sort -d /etc/passwd -o /tmp/look.dict
68 look -t: root:foobar /tmp/look.dict
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71 grep(1), sort(1)
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74 The look command is part of the util-linux package and is available
75 from https://www.kernel.org/pub/linux/utils/util-linux/.
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79util-linux June 2011 LOOK(1)