I want to compare two Debian systems with respect to packages version numbers. For that I need a file listing of all installed packages like this:
a2ps 1:4.14-1.3
abiword 3.0.0-8+b1
acl 0.6.37-3+b1
...
I wrote a bash script (rather clumsy) that collects the required info, but I cannot make it write to a file. Can someone help me to fix this?
dpkg --get-selections \
| grep "\binstall\b" \
| sed 's/\(^[A-Za-z0-9\.\-\_]*\).*/\1/' \
| while read i ; \
do `echo $i` `apt-cache policy $i \
| grep Install \
| sed 's/ *Installed: *\([A-Za-z0-9\.\-\_]*\)/\1/' `\
; done
Thank you.
dpkg-query --show -f '${Package}\t${Version}\n' > out.txt
Related
My task is to grab latest version of maven in bash script using curl https://apache.osuosl.org/maven/maven-3/
Output should be: 3.8.5
curl -s "https://apache.osuosl.org/maven/maven-3/" | grep -o "[0-9].[0-9].[0-9]" | tail -1
works for me ty
One way is to
Use grep to only get the lines containing the folder link
Use sed with an regex to get only the version number
Use sort to sort the lines
Use tail -n1 to get the last line
curl -s https://apache.osuosl.org/maven/maven-3/ \
| grep folder \
| gsed -E 's/.*([[:digit:]]\.[[:digit:]]\.[[:digit:]]).*/\1/' \
| sort \
| tail -n1
Output:
3.8.5
The url you're mentioning is an HTML-document and curl is not an HTML-parser, so I'd look into an HTML-parser, like xidel, if I were you:
$ xidel -s "https://apache.osuosl.org/maven/maven-3/" -e '//pre/a[last()]'
3.8.5/
$ xidel -s "https://apache.osuosl.org/maven/maven-3/" -e 'substring-before(//pre/a[last()],"/")'
3.8.5
I would suggest to use the central repository instead one of the apache maven sites because the information on central more maded for machine consumption.
It will be taken into account that the file maven-metadata.xml contains the appropriate information.
There are two options using the <version>..</version> tag and the <latest>..</latest> tag.
MVNVERSION=$(curl https://repo1.maven.org/maven2/org/apache/maven/maven/maven-metadata.xml \
| grep "<version>.*</version>" \
| tr -s " " \
| cut -d ">" -f2 \
| cut -d "<" -f1 \
| sort -V -r \
| head -1)
The second option:
MVNVERSION=$(curl https://repo1.maven.org/maven2/org/apache/maven/maven/maven-metadata.xml \
| grep "<latest>.*</latest>" \
| cut -d ">" -f2 \
| cut -d "<" -f1)
When I have long multi-line piped commands in my scripts I would like to comment on what each line does, but I haven't found a way of doing so.
Given this snippet:
git branch -r --merged \
| grep " $remote" \
| egrep -v "HEAD ->" \
| util.esed -n 's/ \w*\/(.*)/\1/p' \
| egrep -v \
"$(skipped $skip | util.esed -e 's/,/|/g' -e 's/(\w+)/^\1$/g' )" \
| paste -s
Is it possible to insert comments in between the lines? It seems that using the backslash to escape the newline prevents me from adding comments at the end of the line, and I can't add the comment before the backslash, as that would hide the escaping.
Pseudo-code of what I would like the above script to look like
It seems I was unclear (?) of what I wanted by the above section, so to have a clue on what I am looking for, it should be in the similar vein of this:
git branch -r --merged \ # list merged remote branches
| grep " $remote" \ # filter out the ones for $remote
| egrep -v "HEAD ->" \ # remove some garbage
#strip some whitespace:
| util.esed -n 's/ \w*\/(.*)/\1/p' \
# remove the skipped branches:
| egrep -v \
"$(skipped $skip | util.esed -e 's/,/|/g' -e 's/(\w+)/^\1$/g' )" \
| paste -s # something else
It doesn't have to be exactly like this (obviously, it's not valid syntax), but something similar. If it's not possible directly, due to syntactical restrictions, perhaps it's possible to write self-modifying code that will have comments that are removed before executing it?
You can try something like that:
git branch --remote | # some comment
grep origin | # another comment
tr a-z A-Z
On my Fedora machine I sometimes need to find out certain components of the kernel name, e.g.
VERSION=3.18.9-200.fc21
VERSION_ARCH=3.18.9-200.fc21.x86_64
SHORT_VERSION=3.18
DIST_VERSION=fc21
EXTRAVERSION = -200.fc21.x86_64
I know uname -a/-r/-m but these give me not all the components I need.
Of course I can just disassemble uname -r e.g.
KERNEL_VERSION_ARCH=$(uname -r)
KERNEL_VERSION=$(uname -r | cut -d '.' -f 1-4)
KERNEL_SHORT_VERSION=$(uname -r | cut -d '.' -f 1-2)
KERNEL_DIST_VERSION=$(uname -r | cut -d '.' -f 4)
EXTRAVERSION="-$(uname -r | cut -d '-' -f 2)"
But this seems very cumbersome and not future-safe to me.
Question: is there an elegant way (i.e. more readable and distribution aware) to get all kernel version/name components I need?
Nice would be s.th. like
kernel-ver -f "%M.%m.%p-%e.%a"
3.19.4-200.fc21.x86_64
kernel-ver -f "%M.%m"
3.19
kernel-ver -f "%d"
fc21
Of course the uname -r part would need a bit sed/awk/grep magic. But there are some other options you can try:
cat /etc/os-release
cat /etc/lsb-release
Since it's fedora you can try: cat /etc/fedora-release
lsb_release -a is also worth a try.
cat /proc/version, but that nearly the same output as uname -a
In the files /etc/*-release the format is already VARIABLE=value, so you could source the file directly and access the variables later:
$ source /etc/os-release
$ echo $ID
fedora
To sum this up a command that should work on every system that combines the above ideas:
cat /etc/*_ver* /etc/*-rel* 2>/dev/null
I would like to implement this as a Makefile task:
# step 1:
curl -u username:password -X POST \
-d '{"name": "new_file.jpg","size": 114034,"description": "Latest release","content_type": "text/plain"}' \
https://api.github.com/repos/:user/:repo/downloads
# step 2:
curl -u username:password \
-F "key=downloads/octocat/Hello-World/new_file.jpg" \
-F "acl=public-read" \
-F "success_action_status=201" \
-F "Filename=new_file.jpg" \
-F "AWSAccessKeyId=1ABCDEF..." \
-F "Policy=ewogIC..." \
-F "Signature=mwnF..." \
-F "Content-Type=image/jpeg" \
-F "file=#new_file.jpg" \
https://github.s3.amazonaws.com/
In the first part however, I need to get the file size (and content type if it's easy, not required though), so some variable:
{"name": "new_file.jpg","size": $(FILE_SIZE),"description": "Latest release","content_type": "text/plain"}
I tried this but it doesn't work (Mac 10.6.7):
$(shell du path/to/file.js | awk '{print $1}')
Any ideas how to accomplish this?
If you have GNU coreutils:
FILE_SIZE=$(stat -L -c %s $filename)
The -L tells it to follow symlinks; without it, if $filename is a symlink it will give you the size of the symlink rather than the size of the target file.
The MacOS stat equivalent appears to be:
FILE_SIZE=$(stat -L -f %z)
but I haven't been able to try it. (I've written this as a shell command, not a make command.) You may also find the -s option useful:
Display information in "shell output", suitable for initializing variables.
For reference, an alternative method is using du with -b bytes output and -s for summary only. Then cut to only keep the first element of the return string
FILE_SIZE=$(du -sb $filename | cut -f1)
This should return the same result in bytes as #Keith Thompson answer, but will also work for full directory sizes.
Extra: I usually use a macro for this.
define sizeof
$$(du -sb \
$(1) \
| cut -f1 )
endef
Which can then be called like,
$(call sizeof,$filename_or_dirname)
I think this is a case where parsing the output of ls is legitimate:
% FILE_SIZE=`ls -l $filename | awk '{print $5}'`
(no it's not: use stat, as noted by Keith Thompson)
For the type, you can use
% FILE_TYPE=`file --mime-type --brief $filename`
Is it possible to Wget a page's title from the command line?
input:
$ wget http://bit.ly/rQyhG5 <<code>>
output:
If it’s broke, fix it right - Keeping it Real Estate. Home
This script would give you what you need:
wget --quiet -O - http://bit.ly/rQyhG5 \
| sed -n -e 's!.*<title>\(.*\)</title>.*!\1!p'
But there are lots of situations where it breaks, including if there is a <title>...</title> in the body of the page, or if the title is on more than one line.
This might be a little better:
wget --quiet -O - http://bit.ly/rQyhG5 \
| paste -s -d " " \
| sed -e 's!.*<head>\(.*\)</head>.*!\1!' \
| sed -e 's!.*<title>\(.*\)</title>.*!\1!'
but it does not fit your case as your page contains the following head opening:
<head profile="http://gmpg.org/xfn/11">
Again, this might be better:
wget --quiet -O - http://bit.ly/rQyhG5 \
| paste -s -d " " \
| sed -e 's!.*<head[^>]*>\(.*\)</head>.*!\1!' \
| sed -e 's!.*<title>\(.*\)</title>.*!\1!'
but there is still ways to break it, including no head/title in the page.
Again, a better solution might be:
wget --quiet -O - http://bit.ly/rQyhG5 \
| paste -s -d " " \
| sed -n -e 's!.*<head[^>]*>\(.*\)</head>.*!\1!p' \
| sed -n -e 's!.*<title>\(.*\)</title>.*!\1!p'
but I am sure we can find a way to break it. This is why a true xml parser is the right solution, but as your question is tagged shell, the above it the best I can come with.
The paste and the 2 sed can be merged in a single sed, but is less readable. However, this version has the advantage of working on multi-line titles:
wget --quiet -O - http://bit.ly/rQyhG5 \
| sed -n -e 'H;${x;s!.*<head[^>]*>\(.*\)</head>.*!\1!;T;s!.*<title>\(.*\)</title>.*!\1!p}'
Update:
As explain in the comments, the last sed above uses the T command which is a GNU extension. If you do not have a compatible version, you can use:
wget --quiet -O - http://bit.ly/rQyhG5 \
| sed -n -e 'H;${x;s!.*<head[^>]*>\(.*\)</head>.*!\1!;tnext;b;:next;s!.*<title>\(.*\)</title>.*!\1!p}'
Update 2:
As above still not working on Mac, try:
wget --quiet -O - http://bit.ly/rQyhG5 \
| sed -n -e 'H;${x;s!.*<head[^>]*>\(.*\)</head>.*!\1!;tnext};b;:next;s!.*<title>\(.*\)</title>.*!\1!p'
and/or
cat << EOF > script
H
\$x
\$s!.*<head[^>]*>\(.*\)</head>.*!\1!
\$tnext
b
:next
s!.*<title>\(.*\)</title>.*!\1!p
EOF
wget --quiet -O - http://bit.ly/rQyhG5 \
| sed -n -f script
(Note the \ before the $ to avoid variable expansion.)
It seams that the :next does not like to be prefixed by a $, which could be a problem in some sed version.
The following will pull whatever lynx thinks the title of the page is, saving you from all of the regex nonsense. Assuming the page you are retrieving is standards compliant enough for lynx, this should not break.
lynx -dump example.com | sed '2q;d'