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howtos:general_admin:cli_constructs_and_useful_info [2012/10/21 10:50 (UTC)] htexmexh [Sources] |
howtos:general_admin:cli_constructs_and_useful_info [2012/12/24 12:13 (UTC)] hazel [Useful commands and info] |
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| Line 97: | Line 97: | ||
| bash-4.2$ | bash-4.2$ | ||
| </code> | </code> | ||
| - | Clearly you need to quote a file with spaces. You could use single quotes here, because no variable were inside the quotes. You should not quote in this case: | + | Clearly you need to quote a file with spaces. You could use single quotes here, because no variables were inside the quotes. You should not quote in this case: |
| <code bash> | <code bash> | ||
| bash-4.2$ for i in $(seq 1 10); do printf "$i "; done; echo; | bash-4.2$ for i in $(seq 1 10); do printf "$i "; done; echo; | ||
| Line 148: | Line 148: | ||
| === External Links === | === External Links === | ||
| * http://www.grymoire.com/Unix/Quote.html | * http://www.grymoire.com/Unix/Quote.html | ||
| - | ==== Regex ==== | + | ==== Regular expressions ==== |
| === Basic === | === Basic === | ||
| * ''.'' matches any single character. | * ''.'' matches any single character. | ||
| Line 174: | Line 174: | ||
| * Example: ''\<[tT]he\>'' matches the word ''the'' or ''The''. | * Example: ''\<[tT]he\>'' matches the word ''the'' or ''The''. | ||
| * ''*'' matches any number of the previous character or nothing = no character. Example: ''[0-9]*'' which will match any number of numbers. ''.*'' matches any number of anything. | * ''*'' matches any number of the previous character or nothing = no character. Example: ''[0-9]*'' which will match any number of numbers. ''.*'' matches any number of anything. | ||
| - | === Extended === | + | === Extended regular expressions === |
| The following must be supported by the program for them to work. For example for grep you must run ''egrep'' or ''grep -E''. | The following must be supported by the program for them to work. For example for grep you must run ''egrep'' or ''grep -E''. | ||
| * ''+'' matches any number of the previous character, like ''*'', but there must be at least one to match, so it will not match nothing or no character. | * ''+'' matches any number of the previous character, like ''*'', but there must be at least one to match, so it will not match nothing or no character. | ||
| Line 204: | Line 204: | ||
| </code> | </code> | ||
| === cmp === | === cmp === | ||
| - | This can compare two files byte by byte, and can be more useful that checksums. For example, after you burn a CD/DVD, you can run: | + | This can compare two files byte by byte, and can be more useful than checksums. For example, after you burn a CD/DVD, you can run: |
| <code bash> | <code bash> | ||
| cmp slackware.iso /dev/sr0 | cmp slackware.iso /dev/sr0 | ||
