to be expressed and enclosed by a slash.
For example, search for all rows with the root keyword in/etc/passwd.
awk -F: '/root/' /etc/passwd#resultroot:x:0:0:root:/root:/bin/bashoperator:x:11:0:operator:/root:/sbin/nologin
This is an example of pattern. Only the row matching pattern (root here) can execute action (no action is specified, and the content of each row is output by default ). Regular Expressions are supported in search, for example,
When you uninstall MySQL on Windows, the run fails when you reinstall again, and the following error is reported:Workaround:1. Service inside stop MySQL service.2. Uninstall MySQL and remove the MySQL installation directory.3. Also delete the MySQL-related files from the following directory4. Delete the Heky_local_machine related directory in the registration tableHkey_local_machine\system\controlset001\services\eventlog\application\mysql DirectoryHkey_local_machine\system\controlset002\services
.
ARGC command line parameter count ARGV command line parameter arrangement ENVIRON supports the number of records in the FNR file browsed by FILENAME awk for system environment variables in the queue. FS sets the input domain separator, it is equivalent to the number of domains in the command line-F option NF browsing record NR number of records read OFS output domain separator ORS output record separator
pattern. Only the row matching pattern (root here) can execute action (no action is specified, and the content of each row is output by default ).
Regular Expressions are supported in search, for example, awk-F: '/^ root/'/etc/passwd.
Search for all rows with the root keyword in/etc/passwd and display the corresponding shell
# awk -F: '/root/{print $7}' /etc/passwd /bin/bash
Action {print $7}
In shell commands or programming, awk's powerful text processing capabilities can be used. If you want to format a message or
If data packets are extracted from large text files, awk can complete these tasks. Awk is an explanation.
Programming Language . Awk is also the most difficult to master in Shell filtering tools. Awk
in a) print a[i],i| " Sort-k1-nr|head-n10 "} ' Access.logMethod 2:$ awk ' {print $} ' access.log |sort |uniq-c |sort-k1-nr |head-n10Description: a[$1]++ creates an array A, takes the first column as the subscript, uses the operator + + as the array element, and the element initial value is 0. When processing an IP, the subscript is IP, the element plus 1, proces
Install mysql 5.5.8 Error Nr.1364 authentication_string In the last step of installing mysql 5.5.8. When applying security configuration, the Error dialog box is displayed. Solution to Error Nr.1364 authentication_string: 1. Do not close this window temporarily. cmd command, run mysql-uroot-ppassword to log on to www.2cto.com 2. Run use mysql; alter table 'user' change column 'authentication _ string' text
sensitivity in regular expressions and string operations. The number of NF file domains. The number of records of the current NR file. OFMT digital output format. OFS output domain separator. ORS output record delimiter. The length of the string matching by the match function. RS input record delimiter. The offset of the string matching by the match function. SUBSEP subscript delimiter.
/> Cat employees2Tom Jones: 4424: 5/12/66: 543354Mary Adams: 534
row of records will be read for each call to the getline function. If the variable parameter is not specified, the $0 record variable is set to the value of the record, and the NF, NR, and FNR special variables are also set.
Getline [variable]
Set the variable specified by the variable parameter to the next input record read from the current input file. If the variable parameter is not specified, the $0 record variable is set to the value
awk is a row processor: Compared to the advantages of screen processing, there is no memory overflow or slow processing when processing large files, usually used to format text informationThe awk processing process:Each row is processed in turn, and then the outputawk command form:awk [-f|-f|-v] ' begin{}//{command1; Command2} end{} ' file [-f|-f|-v] Large parameter,-F specify delimiter,-F call script,-v de
How to solve the problem of error Nr.1045 during mysql installation, mysqlnr.1045
When MySQL is installed in windows, the following error occurs: Access denied for user 'root' @ localhost' (using password: No, this problem occurs because you have installed mysql on your machine or configured a new password for this installation, in the last step of the application, the configuration failed due to some reasons such as out of the card or failed to start
The following error occurred in the last step of the MySQL installation:And this is the problem that occurs when the firewall is turned off.The reason is: the previously installed MySQL is not uninstalled cleanly.To uninstall the MySQL step:1. First turn off the MySQL service and then locate MySQL in the Control Panel and uninstall it.2. Delete all files under the installation folder.3. Open the Registration form:Delete Hkey_local_machine\system\controlset001\services\eventlog\application\mysql
Workaround:1. Management tool---Service inside stop MySQL service.2. Control Panel---Uninstall MySQL, delete C:\Program files\mysql directory.3. This is the most critical step, only the first two steps, the password or can not be modified, because MySQL also has files, that is, in C:\Documents and Settings\All Users\Application Data inside the MySQL folder, This file is not cleared and is the source of the old password for MySQL reload. Then delete the MySQL folder. 4. Check if there are my.ini
Tags: style io color ar sp strong file on logWorkaround:1. Management tool---Service inside stop MySQL service.2. Control Panel---Uninstall MySQL, delete C:\Program files\mysql directory.3.This is the most critical step, only the first two steps, the password or can not be modified, because MySQL also has files, that is, in C:\Documents and Settings\All Users\Application Data inside the MySQL folder, This file is not cleared and is the source of the old password for MySQL reload. Then delete the
:\Program files\mysql directory.3. this is the most critical step, only to do the first two steps, the password or can not be modified, because MySQL also has files, that is, in C:\Documents and Settings\All Users\Application Data inside the MySQL folder, This file is not cleared and is the source of the old password for MySQL reload. Then delete the MySQL folder. 4. Check if there is a My.ini file in the C:\WINDOWS directory and delete it5. Heky_local_machine,software,mysql deletion in the regi
Tags: Unix special ike split file FNR proc ... memfreeawk is a row processor: Compared to the advantages of screen processing, there is no memory overflow or slow processing when processing large files, usually used to format text informationThe awk processing process:Each row is processed in turn, and then the outputawk command form:awk [-f|-f|-v] ' begin{}//{command1; Command2} end{} ' file [-f|-f|-v] Large parameter,-F specify delimiter,-F call scr
awk is a row processor: Compared to the advantages of screen processing, there is no memory overflow or slow processing when processing large files, usually used to format text informationThe awk processing process:Each row is processed in turn, and then the outputawk command form:awk [-f|-f|-v] ' begin{}//{command1; Command2} end{} ' file [-f|-f|-v] Large parameter,-F specify delimiter,-F call script,-v de
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