It is probably a problem in understanding, not in using:
Suppose you have a string
and you want to match it, based on the "a" and the "c" occurring. You are looking for one occurrence of "a", followed by whatever, followed by one occurrence of "c". But if you look for "zero (or more) occurrences of 'a'", you basically don't care for the "a" at all - "zero or more" can also be "zero", which means there is no "a" there.
This begs the question what an expression like "a*" is good for, if it means that the "a" is optional at all. Well, suppose the following:
This would match any "x", followed by zero or more "a"s, followed by "y". Strings matched by this would be:
Not matched would be:
In other words: our expression means that between "x" and "y" only "a"s are allowed - regardless how many, even zero - but if there is anything in between "x" and "y" it has to be "a"s and "a"s alone.
hi,
I have
* an IBM P550 machine,
* an AIX 5.3 running on it and
* an oracle database, already installed on it.
The problem (or question of my own) is:
Oracle tns listener, "CT_LISTENER", and the enterprise manager (EM) of the instance, which is uniq instance and called... (0 Replies)
hi,
I have a problem about the Oracle related components. I'm not able to find any answer yet, and waiting for your responses...
Here is the configuration of my system:
* an IBM P550 machine,
* an AIX 5.3 running on it and
* an oracle database, already installed on it.
The problem (or... (1 Reply)
Hi,
I have line in input file as below:
3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL
My expected output for line in the file must be :
"1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL"
Can someone... (7 Replies)
Hello everyone
Sorry I have to add another sed question. I am searching a log file and need only the first 2 occurances of text which comes after (note the space) "string " and before a ",". I have tried
sed -n 's/.*string \(*\),.*/\1/p' filewith some, but limited success. This gives out all... (10 Replies)
logs:
"/home/abc/public_html/index.php"
"/home/abc/public_html/index.php"
"/home/xyz/public_html/index.php"
"/home/xyz/public_html/index.php"
"/home/xyz/public_html/index.php"
how to use "cut" or "awk" or "sed" to get the following result:
abc
abc
xyz
xyz
xyz (8 Replies)
Discussion started by: timmywong
8 Replies
8. Post Here to Contact Site Administrators and Moderators
Majority of the questions are pertaining file/string parsing w.r.t
sed
or
awk
It would be nice to have these two as their own sub category under shell-programming-scripting which can avoid lot of duplicate posts. (1 Reply)
Hi Experts,
I have a string with colon delimited, want 2nd colon to be changed to a pipe.
data:
101:8:43:4:72:14:41:69:85:3:137:4:3:0:4:0:9:3:0:3:12:3:
I am trying with sed, but can change only 1 occurance:
echo "101:8:43:4:72:14:41:69:85:3:137:4:3:0:4:0:9:3:0:3:12:3:" | sed 's/:/|/2'... (5 Replies)
Hi All
I am using GNU/Linux
This is regarding the get command to retrieve files (filename with wild card characters) from remote server.
I thought Get command can retrieve only 1 file irrespective of the files it has on the remote server And it is the function of mget to retrieve all... (7 Replies)
Discussion started by: sparks
7 Replies
LEARN ABOUT CENTOS
yumdb
yumdb(8)yumdb(8)NAME
yumdb - query and alter the Yum database
SYNOPSIS
yumdb [command] [packages ...]
DESCRIPTION
This command is used to query and alter the yum database, which is a simple key value store used in conjunction with the rpm database. Any
installed package can have arbitrary data in the yum database, however the main use case is to store extra data about packages as they are
installed.
yumdb commands are:
yumdb get <key> [pkg-wildcard]...
This command will get the value for the given key, limiting to any specified packages.
yumdb set <key> <value> [pkg-wildcard]...
This command will set the value for the given key, to the given value, limiting to any specified packages.
yumdb del <key> [pkg-wildcard]...
This command will delete the given key, limiting to any specified packages.
yumdb rename <old-key> <new-key> [pkg-wildcard]...
This command will rename the given old-key, to the given new-key, limiting to any specified packages. If the old-key does not exist, noth-
ing happens.
yumdb rename-force <old-key> <new-key> [pkg-wildcard]...
This command will rename the given old-key, to the given new-key, limiting to any specified packages. If the old-key does not exist, new-
key is deleted.
yumdb copy <old-key> <new-key> [pkg-wildcard]...
This command will copy the given old-key, to the given new-key, limiting to any specified packages. If the old-key does not exist, nothing
happens.
yumdb copy-force <old-key> <new-key> [pkg-wildcard]...
This command will copy the given old-key, to the given new-key, limiting to any specified packages. If the old-key does not exist, new-key
is deleted.
yumdb search <key> <wildcard>...
This command will search all packages for the given key, against any of the given wildcard values.
yumdb exist <key> [pkg-wildcard]...
This command will print any packages which have the given key, limiting to any specified packages.
yumdb unset <key> [pkg-wildcard]...
This command will print any packages which do not have the given key, limiting to any specified packages.
yumdb info [pkg-wildcard]...
This command will display all the data stored in the yumdb, limiting to any specified packages.
yumdb sync [pkg-wildcard]...
This command will add any missing data to the yumdb from the repositories, limiting to any specified packages. This is useful to run if you
have had any aborted transactions (and thus. missing yumdb data). Note that "yumdb sync" cannot know all the information that would have
been put into the yumdb at the time.
yumdb sync-force [pkg-wildcard]...
This command will replace any data in the yumdb from the repositories, limiting to any specified packages.
EXAMPLES
List all the packages which don't have a from_repo key/value:
yumdb unset from_repo
List all the packages which were installed as dependencies:
yumdb search reason dep
WELL KNOWN KEYS
Note that there is no limit to the number of keys that can be created or what they may contain (for installed packages only). However this
is a list of well known keys, and what they store.
checksum_data
checksum_type
These keys store the createrepo checksum, and it's type, of the available
package yum installed. Note that these are used by "yum version" to calculate
the rpmdb version.
command_line
This key stores the entire command line, of the yum command (if it was called).
from_repo
from_repo_revision
from_repo_timestamp
These keys take values from the available package yum installed, and store the
repo id, it's revision and timestamp.
reason
This key stores either "user" or "dep", currently. To mark if the user requested
the package to be installed, or if it was brought in automatically as a
dependency. Note that this is kept over updates.
releasever
This key stores the value of releasever, when the package was installed.
installonly
If this attribute has the value "keep" then this package will not be
removed automatically by the installonly process (and does not count towards
the installonly_limit).
SEE ALSO
yum (8)
rpm (8)
AUTHORS
James Antill <james.antill@redhat.com>.
James Antill 8 April 2010 yumdb(8)