Trying to append() to a local file using Fabric.
I'd like to use
append('/etc/ssh_config', ['\n\nHost', '\n\tIdentityFile', '\n\User'])
But unfortunately it only tries on remote files
Attempting to wrap append within local(), like so:
local(append('/etc/ssh_config', ['\n\nHost', '\n\tIdentityFile', '\n\User']))
...fails miserably.
Don't believe so.
If you look at the source code for append it loops through the lines, escapes any regexes in the line and if the line is not already present in file based on a egrep check, it does a echo line >> file
It should be possible to wrap all this up a triple-quoted shell snippet that can then be passed to local
Related
I am creating a python script that uses PyPdf2. I am trying to open and append a file using a wild card in the file name. It is taking the * literally in the file name.
Is there a way to declare wildcards with the open and merge functionality in PyPdf2? And if so, how?
Why not use the glob.glob function to find the list of matching files, then append each individually? That is a far cleaner separation of concerns than expecting PyPDF to guess when you mean a literal filename and when you mean a wildcard.
Background: I have a fairly simple bash script that I'm using to generate a CSV log file. As part of that bash script I poll other devices on my network using netcat. The netcat command returns a stream of information that I can pipe that into a grep command to get to certain values I need in the CSV file. I save that return value from grep into a bash variable and then at the end of the script, I write out all saved bash variables to a CSV file. (Simple enough.)
The change I'd like to make is the amount of netcat commands I have to issue for each piece of information I want to save off. With each issued netcat command I get ALL possible values returned (so each time returns the same data and is burdensome on the network). So, I'd like to only use netcat once and parse the return value as many times as I need to create the bash variables that can later be concatenated together into a single record in the CSV file I'm creating.
Specific Question: Using bash syntax if I pass the output of the netcat command to a file using > (versus the current grepmethod) I get a file with each entry on its own line (presumably separated with the \n as the EOL record separator -- easy for perl regex). However, if I save the output of netcat directly to a bash variable, and echo that variable, all of the data is jumbled together, so it is cumbersome to parse out (not so easy).
I have played with two options: First, I think a perl one-liner may be a good solution here, but I'm not sure how to best execute it. Pseudo code might be to save the netcat output to a a bash variable and then somehow figure out how to parse it with perl (not straight forward though).
The second option would be to use bash's > and send netcat's output to a file. This would be easy to process with perl and Regex given the \n EOL, but that would require opening an external file and passing it to a perl script for processing AND then somehow passing its return value back into the bash script as a bash variable for entry into the CSV file.
I know I'm missing something simple here. Is there a way I can force a newline entry into the bash variable from netcat and then repeatedly run a perl-one liner against that variable to create each of the CSV variables I need -- all within the same bash script? Sorry, for the long question.
The second option would be to use bash's > and send netcat's output to
a file. This would be easy to process with perl and Regex given the \n
EOL, but that would require opening an external file and passing it to
a perl script for processing AND then somehow passing its return value
back into the bash script as a bash variable for entry into the CSV
file.
This is actually a fairly common idiom: save the output from netcat in
a temporary file, then use grep or awk or perl or what-have-you as
many times as necessary to extract data from that file:
# create a temporary file and arrange to have it
# deleted when the script exists.
tmpfile=$(mktemp tmpXXXXXX)
trap "rm -f $tmpfile" EXIT
# dump data from netcat into the
# temporary file.
nc somehost someport > $tmpfile
# extract some information into variable `myvar`
myvar=$(awk '/something/ {print $4}' $tmpfile)
That last line demonstrates how to get the output of something (in this case, an awk script) into a variable. If you were using perl to extract some information you could do the same thing.
You could also just write the whole script in perl, which might make your life easier.
I've got folder with about 1300 png icons. What I need is html file with all of them inside like:
<img src="path-to-image.png" alt="file name without .png" id="file-name-without-.png" class="icon"/>
Its easy as hell but with that number of files its pure waste of time to do it manually. Have you any ideas how to automate it?
If you need it just once, then do a "dir" or "ls" and redirect it to a file, then use an editor with macro-ability like notepad++ to record modifying a single line like you desire, then hit play macro for the remainder of the file. If it's dynamic, use PHP.
I would not use C++ to do this. I would use vi, honestly, because running regular expressions repeatedly is all that is needed for this.
But young an do this in C++. I would start with a plan text file with all the file names generated by Dir or ls on the command prompt.
Then write code that takes a line of input and turns it into a line formatted the way you want. Test this and get it working on a single line first.
The RE engine of C++ is probably overkill (and is not all that well supported in compilers), but substr and basic find and replace is all you need. Is there a string library you are familiar with? std::string would do.
To generate the file name without PNG, check the last four characters and see if they exist and are .PNG (if not report an error). Then strip them. To remove dashes, copy characters to a new string but if you are reading a dash write a space. Everything else is just string concatenation.
I'm working on refactoring a bunch of PHP code for an instructor. The first thing I've decided to do is to update all the SQL files to be written in Drupal SQL coding conventions, i.e., to have all-uppercase keywords. I've written a few regular expressions:
:%s/create table/CREATE TABLE/gi
:%s/create database/CREATE DATABASE/gi
:%s/primary key/PRIMARY KEY/gi
:%s/auto_increment/AUTO_INCREMENT/gi
:%s/not null/NOT NULL/gi
Okay, that's a start. Now I just open every SQL file in Vim, run all five regular expressions, and save. This feels like five times the work it should be. Can they be compounded in to one obnoxiously long but easily copy-pastable regex?
why do you have to do it in vim? how about sed/awk?
e.g. with sed
sed -e 's/create table/\U&/g' -e's/not null/\U&/g' -e 's/.../\U&/' *.sql
btw, in vi you may do
:%s/create table/\U&/g
to change case, well save some typing.
update
if you really want a long command to execute in vi, maybe you could try:
:%s/create table\|create database\|foo\|bar\|blah/\U&/g
Open the file containing that substitution commands.
Copy its contents (to the unnamed register, by default):
:%y
If there is only one file where the substitutions should be
performed, open it as usual and run the contents of that register
as a Normal mode command:
:#"
If there are several files to edit automatically, open those
files as arguments:
:args *.sql
Execute the yanked substitutions for each file in the argument list:
:argdo #"|up
(The :update command running after the substitutions, writes
the buffer to file if it has been changed.)
While sed can handle what you want (hovewer it can be interactive as you requestred by flag 'i'), vim still much powerfull. Once I needed to change last argument in some function call in 1M SLOC code base. The arguments could be in one line or in several lines. In vim I achieved it pretty easy.
You can open all php files in vim at once:
vim *.php
After that run in ex mode:
:bufdo! %s/create table/CREATE TABLE/gi
Repeat the rest of commands. At the end save all the files and exit vim:
:xall
I am trying to open a file in c++ and the server the progam in running on is based on tux.
string filename = "../dir/input.txt"; works but
string filename = "~jal/dir1/dir/input.txt"; fails
Is there any way to open a file in c++ when the filename provided is in the second format?
The ~jal expansion is performed by the shell (bash/csh/whatever), not by the system itself, so your program is trying to look into the folder named ~jal/, not /home/jal/.
I'm not a C coder, but getpwent() may be what you need.
You could scan the string, replacing ~user by the appropriate directory.
The POSIX function wordexp does that, and a few other things
variable substitution, like you can use $HOME
optional command substitution, like $(echo foo) (can be disabled)
arithmetic expansion, like $((3+4))
word splitting, like splitting ~/a ~/b into two words
wildcard expansion, like *.cpp
and quoting, like "~/a ~/b" remains that
Here is a ready piece of code, that performs this task:
How do I expand `~' in a filename like the shell does?