BOOL(1)BOOL(1)NAMEbool - print context matching a boolean expression
SYNOPSISbool [options] EXPRESSION [FILE...]
DESCRIPTION
Bool searches the named input FILEs (or standard input if the file name
- is given) for the context of each pattern in the given EXPRESSION.
If the input is HTML formatted, it is parsed and queried in a single
pass.
By default, bool prints the first occurrence of each pattern in its
context if the EXPRESSION is true. This consists of up to 60 charac‐
ters preceding and following the pattern, until a beginning or end of
paragraph is reached.
OPTIONS-b, --byte-offset
Print the byte offset where the match occurred before each line
of output.
-C NUM, --context=NUM
Print NUM characters (default 60) of output context for each
pattern.
-c, --count
Suppress normal output; instead print a count of matching pat‐
terns for each input file.
-D NUM, --distance=NUM
Find patterns separated by NUM words (default 10) when using the
NEAR operator.
-F, --fixed-string
Interpret EXPRESSION as a fixed string instead of a boolean
expression.
-H, --with-filename
Print the filename for each match.
-h, --no-filename
Suppress the prefixing of filenames on output when multiple
files are searched.
--help Output a brief help message.
-i, --ignore-case
Ignore case distinctions in both the EXPRESSION and the input
files.
-L, --files-without-match
Suppress normal output; instead print the name of each input
file from which no output would normally have been printed.
-l, --files-with-matches
Suppress normal output; instead print the name of each input
file from which output would normally have been printed.
-n, --line-number
Prefix each line of output with the line number within its input
file.
-O NUM, --occurrences=NUM
Print NUM lines (default 1) of context for each pattern. No
output is printed if the boolean expression is false. Every
match is printed if NUM is set to 0, even if the expression if
false.
-P, --with-pattern
Print the pattern for each match.
-p, --no-pattern
Suppress the prefixing of patterns on output.
-q, --quiet, --silent
Quiet; suppress normal output. Also see the -s or --no-mes‐
sages option below.
-s, --no-messages
Suppress error messages about nonexistent or unreadable files.
-V, --version
Print the version number of bool to standard error. This ver‐
sion number should be included in all bug reports (see below).
BOOLEAN EXPRESSION
A boolean expression is composed of operands separated by operators.
The precedence of operators is evaluated from left to right.
Operands can be another boolean expression isolated between parentheses
or a pattern. The latter is expressed as a sequence of characters
delimited by spaces or enclosed in quotes. Some characters can be
escaped using the backslash ('\'), other characters can be specified as
SGML entities.
An operand must return a truth value. For a parenthesized expression,
each operator within the expression is evaluated as described below.
For a pattern, the operand is true if there are one or more occurrences
of the sequence of characters in the input. Otherwise, the operand is
false.
Operators are symbols denoting the logic to be performed. The AND
operator returns true if the operands on both sides of the symbol are
true, otherwise the expression is considered false. The OR operator
returns true if either operand is true. The NOT operator returns true
if the left operand is true and the right operand is false.
The NEAR operator, though not boolean, returns true if the operands on
either side of the operator are within a specified number of words from
each other. For example, the words "boolean" and "either" are sepa‐
rated by 6 words in the previous sentence. If the distance specified
on the command-line is 10, the expression is true.
DIAGNOSTICS
Normally, exit status is 0 if matches were found, and 1 if no matches
were found. Exit status is 2 if there were syntax errors in the
expression or other system errors.
EXAMPLES
Output the first context where 'one' and 'two' are found, only if both
are present:
# bool "one and two"
All occurences of 'one' and 'two'. If the boolean expression is false,
ie if only 'one' or 'two' is present, the return value is 1:
# bool-O0 "one and two"
Every byte offset where 'two' is separated from 'three' by no more than
5 words, but don't print any context:
# bool-O0 -C0 -D5 -b "two near three"
Only return the status of the boolean expression, 0 if matches were
found and 1 otherwise:
# bool-q "one and (two near three)"
AUTHOR
Marc Tardif <intmktg@cam.org>
SEE ALSOgrep(1)
GNU Project BOOL(1)
