Unix 从文本文件中获取特定行
我正在一个UNIX机器上工作,并尝试运行一个应用程序,该应用程序为标准输出提供一些调试日志。我已将此输出重定向到日志文件,但现在希望获得显示错误的行 我的问题是一个简单的Unix 从文本文件中获取特定行,unix,shell,file-io,Unix,Shell,File Io,我正在一个UNIX机器上工作,并尝试运行一个应用程序,该应用程序为标准输出提供一些调试日志。我已将此输出重定向到日志文件,但现在希望获得显示错误的行 我的问题是一个简单的 cat output.log | grep FAIL 没有帮助。因为这只显示了发生故障的线路。我想知道更多的信息。就像这条线上面的2-3条线一样。有没有办法通过一个简单的shell命令来实现这一点?我希望有一个命令行(可以有管道)来执行上述操作。grep-a$NUM 这将在匹配后打印尾随上下文的$NUM行 -B$NUM打印前
cat output.log | grep FAIL
没有帮助。因为这只显示了发生故障的线路。我想知道更多的信息。就像这条线上面的2-3条线一样。有没有办法通过一个简单的shell命令来实现这一点?我希望有一个命令行(可以有管道)来执行上述操作。grep-a$NUM
这将在匹配后打印尾随上下文的$NUM行
-B$NUM打印前导上下文
格雷普是你最好的朋友
因此,在你的情况下:
cat日志| grep-A 3-B 3失败
请注意,这也可以通过以下方式消除。:
-B、 --before context=NUM打印前导上下文的行数
-A、 --after context=NUM打印尾随上下文的行数
-C、 --context=NUM打印输出上下文的行数
-NUM与--context=NUM相同
我有两个我称之为
sgrep
的实现,一个用Perl实现,一个只使用pre-Perl(pre-GNU)标准Unix命令。如果你有GNUgrep
,你就没有特别的需求了。处理向前和向后上下文搜索会更复杂,但这可能是一个有用的练习
Perl解决方案:
#!/usr/perl/v5.8.8/bin/perl -w
#
# @(#)$Id: sgrep.pl,v 1.6 2007/09/18 22:55:20 jleffler Exp $
#
# Perl-based SGREP (special grep) command
#
# Print lines around the line that matches (by default, 3 before and 3 after).
# By default, include file names if more than one file to search.
#
# Options:
# -b n1 Print n1 lines before match
# -f n2 Print n2 lines following match
# -n Print line numbers
# -h Do not print file names
# -H Do print file names
use strict;
use constant debug => 0;
use Getopt::Std;
my(%opts);
sub usage
{
print STDERR "Usage: $0 [-hnH] [-b n1] [-f n2] pattern [file ...]\n";
exit 1;
}
usage unless getopts('hnf:b:H', \%opts);
usage unless @ARGV >= 1;
if ($opts{h} && $opts{H})
{
print STDERR "$0: mutually exclusive options -h and -H specified\n";
exit 1;
}
my $op = shift;
print "# regex = $op\n" if debug;
# print file names if -h omitted and more than one argument
$opts{F} = (defined $opts{H} || (!defined $opts{h} and scalar @ARGV > 1)) ? 1 : 0;
$opts{n} = 0 unless defined $opts{n};
my $before = (defined $opts{b}) ? $opts{b} + 0 : 3;
my $after = (defined $opts{f}) ? $opts{f} + 0 : 3;
print "# before = $before; after = $after\n" if debug;
my @lines = (); # Accumulated lines
my $tail = 0; # Line number of last line in list
my $tbp_1 = 0; # First line to be printed
my $tbp_2 = 0; # Last line to be printed
# Print lines from @lines in the range $tbp_1 .. $tbp_2,
# leaving $leave lines in the array for future use.
sub print_leaving
{
my ($leave) = @_;
while (scalar(@lines) > $leave)
{
my $line = shift @lines;
my $curr = $tail - scalar(@lines);
if ($tbp_1 <= $curr && $curr <= $tbp_2)
{
print "$ARGV:" if $opts{F};
print "$curr:" if $opts{n};
print $line;
}
}
}
# General logic:
# Accumulate each line at end of @lines.
# ** If current line matches, record range that needs printing
# ** When the line array contains enough lines, pop line off front and,
# if it needs printing, print it.
# At end of file, empty line array, printing requisite accumulated lines.
while (<>)
{
# Add this line to the accumulated lines
push @lines, $_;
$tail = $.;
printf "# array: N = %d, last = $tail: %s", scalar(@lines), $_ if debug > 1;
if (m/$op/o)
{
# This line matches - set range to be printed
my $lo = $. - $before;
$tbp_1 = $lo if ($lo > $tbp_2);
$tbp_2 = $. + $after;
print "# $. MATCH: print range $tbp_1 .. $tbp_2\n" if debug;
}
# Print out any accumulated lines that need printing
# Leave $before lines in array.
print_leaving($before);
}
continue
{
if (eof)
{
# Print out any accumulated lines that need printing
print_leaving(0);
# Reset for next file
close ARGV;
$tbp_1 = 0;
$tbp_2 = 0;
$tail = 0;
@lines = ();
}
}
sgrep
的shell版本于1989年2月编写,bug于1989年5月修复。然后它保持不变,除了1997年的行政变更(SCCS到RCS的过渡),直到2007年,我添加了-h
选项。我在2007年切换到Perl版本。
您可以使用sed
打印特定行,假设您想要第20行
sed'20p'-n
FILE\u您想要的\u行\u来自
完成了
-n防止从文件中回显行。引号中的部分是要应用的
sed
规则,它指定要将规则应用到第20行,并且要打印。能否显示日志文件的格式?虽然-B和-A确实有效,但它们只是丑陋的黑客。您的一些日志可能更长。例如,如果您在失败中每行缩进\t,您可以更精确地筛选出一个条目,这与GNU grep很好地配合;不是标准(POSIX,Unix)grep.btw的一部分,我知道这个问题的标签是“Unix”,我只是在Windows上测试了一下。
$ grep --context 3 FAIL output.log
$ grep --help | grep context
-B, --before-context=NUM print NUM lines of leading context
-A, --after-context=NUM print NUM lines of trailing context
-C, --context=NUM print NUM lines of output context
-NUM same as --context=NUM
#!/usr/perl/v5.8.8/bin/perl -w
#
# @(#)$Id: sgrep.pl,v 1.6 2007/09/18 22:55:20 jleffler Exp $
#
# Perl-based SGREP (special grep) command
#
# Print lines around the line that matches (by default, 3 before and 3 after).
# By default, include file names if more than one file to search.
#
# Options:
# -b n1 Print n1 lines before match
# -f n2 Print n2 lines following match
# -n Print line numbers
# -h Do not print file names
# -H Do print file names
use strict;
use constant debug => 0;
use Getopt::Std;
my(%opts);
sub usage
{
print STDERR "Usage: $0 [-hnH] [-b n1] [-f n2] pattern [file ...]\n";
exit 1;
}
usage unless getopts('hnf:b:H', \%opts);
usage unless @ARGV >= 1;
if ($opts{h} && $opts{H})
{
print STDERR "$0: mutually exclusive options -h and -H specified\n";
exit 1;
}
my $op = shift;
print "# regex = $op\n" if debug;
# print file names if -h omitted and more than one argument
$opts{F} = (defined $opts{H} || (!defined $opts{h} and scalar @ARGV > 1)) ? 1 : 0;
$opts{n} = 0 unless defined $opts{n};
my $before = (defined $opts{b}) ? $opts{b} + 0 : 3;
my $after = (defined $opts{f}) ? $opts{f} + 0 : 3;
print "# before = $before; after = $after\n" if debug;
my @lines = (); # Accumulated lines
my $tail = 0; # Line number of last line in list
my $tbp_1 = 0; # First line to be printed
my $tbp_2 = 0; # Last line to be printed
# Print lines from @lines in the range $tbp_1 .. $tbp_2,
# leaving $leave lines in the array for future use.
sub print_leaving
{
my ($leave) = @_;
while (scalar(@lines) > $leave)
{
my $line = shift @lines;
my $curr = $tail - scalar(@lines);
if ($tbp_1 <= $curr && $curr <= $tbp_2)
{
print "$ARGV:" if $opts{F};
print "$curr:" if $opts{n};
print $line;
}
}
}
# General logic:
# Accumulate each line at end of @lines.
# ** If current line matches, record range that needs printing
# ** When the line array contains enough lines, pop line off front and,
# if it needs printing, print it.
# At end of file, empty line array, printing requisite accumulated lines.
while (<>)
{
# Add this line to the accumulated lines
push @lines, $_;
$tail = $.;
printf "# array: N = %d, last = $tail: %s", scalar(@lines), $_ if debug > 1;
if (m/$op/o)
{
# This line matches - set range to be printed
my $lo = $. - $before;
$tbp_1 = $lo if ($lo > $tbp_2);
$tbp_2 = $. + $after;
print "# $. MATCH: print range $tbp_1 .. $tbp_2\n" if debug;
}
# Print out any accumulated lines that need printing
# Leave $before lines in array.
print_leaving($before);
}
continue
{
if (eof)
{
# Print out any accumulated lines that need printing
print_leaving(0);
# Reset for next file
close ARGV;
$tbp_1 = 0;
$tbp_2 = 0;
$tail = 0;
@lines = ();
}
}
#!/bin/ksh
#
# @(#)$Id: old.sgrep.sh,v 1.5 2007/09/15 22:15:43 jleffler Exp $
#
# Special grep
# Finds a pattern and prints lines either side of the pattern
# Line numbers are always produced by ed (substitute for grep),
# which allows us to eliminate duplicate lines cleanly. If the
# user did not ask for numbers, these are then stripped out.
#
# BUG: if the pattern occurs in in the first line or two and
# the number of lines to go back is larger than the line number,
# it fails dismally.
set -- `getopt "f:b:hn" "$@"`
case $# in
0) echo "Usage: $0 [-hn] [-f x] [-b y] pattern [files]" >&2
exit 1;;
esac
# Tab required - at least with sed (perl would be different)
# But then the whole problem would be different if implemented in Perl.
number="'s/^\\([0-9][0-9]*\\) /\\1:/'"
filename="'s%^%%'" # No-op for sed
f=3
b=3
nflag=no
hflag=no
while [ $# -gt 0 ]
do
case $1 in
-f) f=$2; shift 2;;
-b) b=$2; shift 2;;
-n) nflag=yes; shift;;
-h) hflag=yes; shift;;
--) shift; break;;
*) echo "Unknown option $1" >&2
exit 1;;
esac
done
pattern="${1:?'No pattern'}"
shift
case $# in
0) tmp=${TMPDIR:-/tmp}/`basename $0`.$$
trap "rm -f $tmp ; exit 1" 0
cat - >$tmp
set -- $tmp
sort="sort -t: -u +0n -1"
;;
*) filename="'s%^%'\$file:%"
sort="sort -t: -u +1n -2"
;;
esac
case $nflag in
yes) num_remove='s/[0-9][0-9]*://';;
no) num_remove='s/^//';;
esac
case $hflag in
yes) fileremove='s%^$file:%%';;
no) fileremove='s/^//';;
esac
for file in $*
do
echo "g/$pattern/.-${b},.+${f}n" |
ed - $file |
eval sed -e "$number" -e "$filename" |
$sort |
eval sed -e "$fileremove" -e "$num_remove"
done
rm -f $tmp
trap 0
exit 0