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| PARAGREP(1) | FreeBSD General Commands Manual | PARAGREP(1) |
NAME
paragrep - search paragraphs in a file for patternsSYNOPSIS
paragrep [ -aiotv ] [ -p eop_expression ] [ -e expression ] [ -f exp_file ] ... [ file ] ...or
paragrep [ -itv ] [ -p eop_expression ] expression [ file ] ...
DESCRIPTION
Paragrep is a paragraph grep utility. It searches for a series of regular expressions in a text file (or several text files) and prints out the paragraphs containing those expressions. Normally a paragraph is displayed if it contains any of the expressions; this behavior can be modified by using the -a option.By default, a paragraph is defined as a block of text delimited by an empty or blank line; this behavior can be altered with the -p option.
If no files are specified on the command line, paragrep searches standard input.
OPTIONS
- -a
- The "and" option: Only display a paragraph if it contains all the regular expressions specified. The default is to display a paragraph if it contains any of the regular expressions specified. (See the -o option, below.)
- -e expression
- Adds a regular expression to the set of expressions against which paragraphs are to be matched. More than one -e argument may be specified. If only one expression is specified, the -e may be omitted, as in the second form of the command, above.
- -f expfile
- Specifies a file containing regular expressions, one expression per line. Each expression in the file is added to the set of expression against which paragraphs are to be matched. More than one -f argument is permitted. Also, -f and -e may be specified together.
- -i
- Considers upper- and lower-case letters to be identical when making comparisons.
- -o
- The "or" option: Display a paragraph if it contains any of the regular expressions specified. Since this option is the default, it is rarely specified on the command line. It exists primarily to negate the effect of a previous -a option. (e.g., If you've defined an alias for paragrep that specifies the -a option, -o would be necessary to force the "or" behavior.)
- -p eop_expression
- Specifies a regular expression to be used match paragraph delimiters. Any line that matches this regular expression is assumed to delimit paragraphs without actually being part of a paragraph (i.e., lines matching this expression are never printed). If this option is not specified, it defaults to `^[ \t]*$' which matches blank or empty lines. (`\t' represents the horizontal tab character. If you need to specify a horizontal tab, you'll need to type the actual character; paragrep doesn't recognize C-style metacharacters.)
- -v
- Displays all lines that do not match specified expressions. The negation logic works on DeMorgan's Laws. Normally, if -a is specified, paragrep uses the following logic to match the paragraph:
- Specifying -v along with -a changes this logic to:
- Likewise, without -a or -v (i.e., using the -o option, which is the default) the matching logic is:
- Negating that logic with -v causes paragrep to match paragraphs with:
SEE ALSO
ed(1), grep(1), perl(1)BUGS
Paragrep's notion of troff directives is overly restrictive. To be less restrictive, you must conjure up a more complicated -p value.Paragrep reads each paragraph into a perl array before scanning it for matches; as a result, extremely long paragraphs can suck up memory.
The logic behind how -v works can be confusing to the uninitiated.
AUTHOR
Brian M. Clapper,http://www.clapper.org/bmc/ @@LICENSE@@
| 8 April 1995 |
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