I have a text file with a large amount of data which is tab delimited. I want to have a look at the data such that I can see the unique values in a column. For example, Red Ball 1 Sold Blue Bat 5 OnSale ............... So, its like the first column has colors, so I want to know how many different unique values are there in th...
I have a script that looks something like this: export foo=/tmp/foo export bar=/tmp/bar Every time I build I run 'source init_env' (where init_env is the above script) to set up some variables To accomplish the same in python I had this code running reg = re.compile('export (?P<name>\w+)(\=(...
I'm curious about what exactly the following comparison does, in as much detail as possible, especially relating to the 0x2 and the & characters and what exactly they do, if [ $((${nValid} & 0x1)) -eq 1 ]; then #...snip... fi if [ $((${nValid} & 0x2)) -eq 2 ]; then #...snip... fi ...
When using eshell or ansi-term and bash emacs changes the default-directory variable depending on what directory you are in. So if I move to /home/user/code/project and then use ido-find-file to open a file it starts ido with the CWD. If I use ksh (my normal shell) or zsh (tried for testing) it doesnt work. Is there a setting or is this...
I saw a bash command sed 's%^.*/%%' Usually the common syntax for sed is sed 's/pattern/str/g', but in this one it used s%^.* for the s part in the 's/pattern/str/g'. My questions: What does s%^.* mean? What's meaning of %% in the second part of sed 's%^.*/%%'? ...
I was trying to set up a bash command in Terminal on a Mac. The scripts run correctly when I execute them directly. I set up symlinks in /usr/local/bin/ to the current location of the scripts. When I try to run it off the symlink, it doesn't work. I don't believe the issue is the $PATH, because pip, git, ipython all exist in this loc...
I have been trying to get the unique values in each column of a tab delimited file in bash. So, I used the following command. cut -f <column_number> <filename> | sort | uniq -c It works fine and I can get the unique values in a column and its count like 105 Linux 55 MacOS 500 Windows What I want to do is instead of sorting by th...
I often need to kill a process during programming. The way I do it now is: [~]$ ps aux | grep 'python csp_build.py' user 5124 1.0 0.3 214588 13852 pts/4 Sl+ 11:19 0:00 python csp_build.py user 5373 0.0 0.0 8096 960 pts/6 S+ 11:20 0:00 grep python csp_build.py [~]$ kill 5124 How can I extract the process id ...
Hello, I was wondering if they was a way to prevent some commands from being executed in order to prevent from bad manipulation sometimes (for exemple you execute "rm *.py" when you wanted to execute "rm *.pyc" or something like that). People will say that it's the user's responsability to check his inputs and it's right but I would li...
Hi everyone, below is an extract from a shell script i am tring to make, it is supposed to allow a user to supply files they want to view and the script prints the first lines of the each file and asks if they want to delete them. i have marked where the errors are, i know i am using the $ improperly. any help would be appreciated t...
My situation is the following: a big (10GB) compressed file containing some files (~60) with a total uncompressed size of 150GB. I would like to be able to slice big compressed log files into parts that have a certain number of lines in them (ie: 1 million). I don't want to use split since it involves totally decompressing the original...
I created a bash script that opens several gnome-terminals, connect to classroom computers via ssh and run a script. How can I avoid that the gnome-terminal closes after the script is finished? Here is an example of my code: gnome-terminal -e "ssh root@ cd /tmp && ls" thx for your help ...
I have few long commands that I will be using on a day to day basis. So I though it would be better to have a bash script where I could pass arguments, thus saving typing. I guess this is the norm in Linux but I am kind of new to it. Could someone show me how to do it. A example is the following command cut -f <column_number> <filename>...
Various bash commands I use -- fancy diffs, build scripts, etc, produce lots of color output. When I redirect this output to a file, and then cat or less the file later, the colorization is gone -- presumably b/c the act of redirecting the output stripped out the color codes that tell the terminal to change colors. Is there a way to ca...
I have the following XML output when I grep for "Server": <Server id="1" src="/other/Server/PRX01/PRX01.xml"/> <Server id="2" src="/other/Server/PRX01/PRX02.xml"/> <Server id="3" src="/other/Server/PRX01/PRX03.xml"/> <Server id="4" src="/other/Server/PRX01/PRX04.xml"/> I need to be able to take this output and sed/awk or some other to...
I need to read a directory structure from the file system and cache it in an xml document. Can someone suggest me on how to do that using bash ? I only need to cache the directories/subdirectories not files under them . The structure is randomly generated , so don't know how many nodes and how much the depth of the tree would be each ...
After enter set -e in an interactive bash, bash will exit immediately if any command exits with non-zero. How can I undo this effect? Thanks. ...
I want to define a constant inside a function that could be used outside the function's scope. function section { variable = "Hello" } echo variable Is this possible? ...
I'm looking for some backup solution. My request is pretty simple: Source - FTP credentials (ftp://user:[email protected]/dir1/dir2) Destination on local HDD (/var/backup/server-tld) Possibility of packing to archive (tar.gz/zip) Plan this "script" as a cron job with defined period (e.g. once a day) I know, that all this can be done us...
I'm trying to write a small command launcher application, and would like to use bash's tab completions in my own completion system. I've been able to get a list of completions for general commands using compgen -abck. However, I would also like to get completions for specific commands: for instance, the input git p should display complet...