Questions about bash only, as opposed to other Bourne/POSIX shells. For all Bourne/POSIX-style shells, use the /shell tag instead.

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3
votes
2answers
739 views

pure shell complex substitution in variable

However it may be impossible, I hope I'm just bad man reader =) Is there any way to substitute text in variables on several patterns at time or even using back reference? For example, I have ...
12
votes
4answers
3k views

How can I find a rogue alias declaration?

I'm trying to find where a specific alias has been declared. I've searched all the usual places I know to look for aliases: ~/.bashrc ~/.bash_profile /etc/bashrc /etc/profile With no luck. I know ...
6
votes
3answers
1k views

Glob with Numerical Order

I have this list of pdf files in a directory: c0.pdf c12.pdf c15.pdf c18.pdf c20.pdf c4.pdf c7.pdf c10.pdf c13.pdf c16.pdf c19.pdf c2.pdf c5.pdf c8.pdf c11.pdf c14.pdf c17.pdf c1.pdf ...
5
votes
2answers
3k views

What causes ln: //: Is a directory?

When linking a directory to root, I get this error: $ ln -s ~/inbox/ / $ ln: //: Is a directory Bash autocompletes the directory path by adding a /. I've tried escaping without success. $ ln -s ...
3
votes
1answer
545 views

KSH styling text based menu using STDERR

Is it possible to format the STDERR in order to have a better looking menu using the select command? I have a simple select select oChoice in $(<tempMenu.menu) ; do case "$oChoice" in ...
14
votes
3answers
5k views

Switching to `zsh`: Are all bash scripts compatible with `zsh`?

I'm looking to switch from bash to zsh but concerned about compatibility of bash scripts. Are all bash scripts/functions compatible with zsh? Therefore, if that is true is zsh just an enhancement to ...
20
votes
3answers
986 views

Where can I find documentation about the “sudo !!” command

I just learned that Linux has a sudo !! command which literally applies sudo to the last entered command. I had never heard about it. Is that a common control? Where can I find documentation about ...
12
votes
4answers
7k views

How can I force unzip / zip not to create a subdirectory when I extract it?

Depending on how a zip file is created, sometimes it will extract all of the files directly, and sometimes it will extract the files into a subdirectory. If the latter is true, how can I force the ...
4
votes
3answers
474 views

Does bash have a built in caching command available (sort of like mktemp or sponge)?

I'm using the amazon ec2 command line tools, and the ec2-describe-instances tool is a little painful because of the 2-5 seconds it requires to make the request and display the output. I'm looking ...
8
votes
4answers
3k views

How can I save the last command to a file?

When I am running my analyses using the bash shell, I often want to save the commands I've used that gave me good results to a file in the same directory (my "LOGBOOK", as its called) so that I can ...
8
votes
4answers
5k views

Remove files older than 5 days in UNIX (date in file name, not timestamp)

I want to delete log files which are older than 5 days from a directory. But deletion should not be based on the timestamp of file. It should be based on the name of file. For Example todays date is ...
2
votes
0answers
187 views

What is and how to use PS1 \#

I put this is .bashrc # colors NC="$(tput sgr0)" RED="$(tput setaf 1)" GREEN="$(tput setaf 2)" # etc ... PS1="\[$BROWN\]\u \[$CYAN\]#\# \[$PINK_BLD\]!\!\[$NC\] \[$BLUE\]\W: \[$NC\]" So deepo #50 ...
1
vote
3answers
155 views

Is there a way to determine when a binary was compiled or installed?

Is there a way to determine when a binary was compiled or installed? For example, I have a binary mdrun_d, and I would like to know when this particular binary was compiled or installed. The system ...
2
votes
1answer
144 views

How do I detect whether changes in nano were discarded or saved?

I am currently writing a small setup script for a Linux application that needs the user to edit a configuration file before the application is started. I've chosen to make the script simply open the ...
1
vote
1answer
19k views

How do I execute a remote shell script over SSH and be prompted for passwords by commands that require it in that script?

I want to do something like this ssh user@remote-domain.com ./remote_script.sh Contents of remote_script.sh #!/bin/bash hg pull This example is much simpler than what I am actually doing. I know ...
4
votes
4answers
929 views

How to add a line to a file which has only root write permission and to continue the script execution

I am trying to learn bash scripting. I am working on a practical problem and at one point I need to add a line to a file which requires root permission to write. The code looks like this: # some ...
12
votes
2answers
29k views

How do I delete the first n lines of an ascii file using shell commands?

I have multiple files that contain ascii text information in the first 5-10 lines, followed by well-tabulated matrix information. In a shell script, I want to remove these first few lines of text so ...
2
votes
1answer
113 views

When is using ~+ useful?

As I understand it, ~+ means the same thing as "the current working directory". So echo ~+ should print the same as pwd. What is the purpose of this tilde expansion ~+ ?
0
votes
1answer
242 views

Fedora 7 server export in .bashrc not getting set [duplicate]

I'm trying to set the JAVA_HOME environment variable in my .bashrc but every time I log back in it gets unset again to its original value, below is my .bashrc file # .bashrc # User specific aliases ...
2
votes
1answer
363 views

Why doesnt ctrl+d work with this?

I wanted a simple way to process text in my clipboard without having to create a file. I tried using the following line: awk '{print $1}' <(cat) but I couldn't send cat the EOF character using ...
5
votes
2answers
922 views

How to enable tab completion of wildcards in bash?

How can I enable tab completion in bash for a statement such as vim db/migrate/*crea? Essentially I am looking for tab completion to match the regular expression and present the options. How would ...
3
votes
2answers
549 views

Insert multiline text into several files via commandline

I want to insert some code into multiple tex files foo*.tex in a directory, one line after \documentclass{.*}. Note that the files have different document classes so the .* is just a symbolic ...
5
votes
1answer
1k views

Get “date” to understand a timestamp phrase of a different language

My web-scraping scripts have long enjoyed using date -d to read in human-formatted time and date stamps like "March 11, 1999" and convert to any other format I need via the -s parameter. How might I ...
3
votes
2answers
493 views

Compile all tex files in a directory

If I do pdflatex *.tex in a directory, only one tex file is compiled. Which syntax should I use that all *.tex files in the directory are compiled?
11
votes
3answers
577 views

Order of redirections

I don't quite understand how the computer reads this command. cat file1 file2 1> file.txt 2>&1 If I understand, 2>&1 simply redirect Standard Error to Standard Output. By that ...
8
votes
4answers
7k views

Delete files of certain size range

I want to delete files which size is between certain values. For example I have the following list of files: -rw-r--r-- 1 smsc sys 558 Apr 30 13:07 stats.sfe.1.20120430130513.xml.Z -rw-r--r-- 1 smsc ...
6
votes
1answer
219 views

Is there a reverse of yank-last-arg/insert-last-argument?

yank-last-arg / insert-last-argument is probably better known by its usual shortcut, Alt-.. It's very nice to navigate through the last argument of earlier commands, but if you're navigating a little ...
2
votes
1answer
2k views

Determine current shell name [duplicate]

Possible Duplicate: How to test what shell I am using in a terminal? How do I determine the current shell path or shell name? I only really need to distinguish sh and bash, however a ...
5
votes
1answer
165 views

What does “:>” do here?

I saw some postinst script # setting wget options :> wgetrc echo "noclobber = off" >> wgetrc echo "dir_prefix = ." >> wgetrc echo "dirstruct = off" >> wgetrc ...
2
votes
3answers
320 views

`$RANDOM` is not random within `find`'s `-exec`

I'm trying to find and move a whole bunch of folders on a linux box. All the folders are named the same, so I am using echo $RANDOM to provide a random number to use for a folder name. echo $RANDOM ...
40
votes
3answers
19k views

Multiline shell script comments - how does this work?

Recently, I stumbled upon a multiline comment type I have never seen before - here is a script example: echo a # : aaa : ddd # echo b This seems to work, hell, even vim syntax-highlights it. What ...
2
votes
2answers
980 views

Bash prompt when my home directory is a symbolic link

I symlinked my /host/Users/Kevin folder to /home/Kevin. I also edit the /etc/passwd file to /home/Kevin. I logged out and logged back in, however when I open up a terminal it's a bash prompt like so: ...
0
votes
1answer
97 views

Alt-Left on OSX to behave like Alt-Left on Ubuntu [duplicate]

Possible Duplicate: How to change previous/next word shortcut in bash? When connected to a ubuntu server bash shell, I can hold alt key and press the left or right keys to move forward or ...
0
votes
4answers
2k views

Renaming files works, but soft links point to the old names. How can I fix that?

For example, I'm renaming many files inside a tree like this: [bash]$ for file in `find . -name "*gsf*"`; do `mv $file ${file/gsf/msf}`; done That renames all the instances of "gsf" in file names ...
1
vote
2answers
3k views

Using awk to process ls output with spaces in filenames/paths

All, I have a script in which I use find command to filter out all png files in a given folder and list them along with their size. I want the output in the following format: someFile.png => 1.2K ...
5
votes
4answers
22k views

Change font in echo command

Is it possible to change the font attributes of the output of echo in either zsh or bash? What I would like is something akin to: echo -n "This is the font: normal " echo -n $font=italic "italic," ...
46
votes
5answers
2k views

cd by just typing the directory's name?

I either had this somewhere 20 years ago or I dreamed about it. Basically: If if type blobblob I get blobblob: command not found Fair enough. I would like it so that when my shell gets those ...
5
votes
4answers
906 views

For each subfolder, sort files by name and rename them to sequential padded numbers (regardless of extension)

I have the following directory structure: . ├── event-a │   ├── album-a │   │   ├── a.jpg │   │   └── x.png │   └── album-b │   ├── a.jpg │   ├── x.png │   └── y.gif └── event-b ├── ...
57
votes
4answers
8k views

What is the difference between “&&” and “;” when chaining commands

What is the difference between the following methods of chaining commands? cmd1; cmd2 cmd1 && cmd2
4
votes
1answer
964 views

bash readline: Key binding that executes an external command

(Background: I'm a long-time tcsh user, gradually transitioning to bash, and trying to find equivalents for some useful tcsh-specific features.) In tcsh, I can define a key binding that executes an ...
3
votes
2answers
314 views

Is there a way to make the history when pressing up in bash shared between shells?

I've seen this answer: Preserve bash history in multiple terminal windows This works for history, but I'm wondering if there is way to extend this so pressing "up" is shared as well?
1
vote
0answers
164 views

Editing images with sips doesn't work without being executed directly from Terminal? [closed]

I made a cheesy application with a bash script using CocoaDialog, and within this application I need to modify the size of a photo. So, I researched a little and found the sips command; and it works ...
2
votes
3answers
2k views

Change Hostname is Bash Prompt

I have changed the hostname and hosts file in /etc, however my bash prompt has not changed, do I need to restart something (like the OS?) for this to take effect?
7
votes
2answers
3k views

Get a progress indicator when importing MySQL databases

I often import MySQL databases, and this can take a while. There is no progress indicator whatsoever. Can one be shown, somehow? Either records imported, MB imported, or tables imported... anything is ...
3
votes
3answers
4k views

using stat to provide timestamp for touch

Am trying to OCR some documents insitu (from a linux command line on a windows share). The process of OCRing is find and I have muddled through using the find command to pipe the files through the ...
4
votes
2answers
7k views

Where is the system profile that gets sourced at login on CentOS 5.8?

In CentOS release 5.8 (Final), where is the bash system profile? Is it /etc/profile ? I've added the following to source my ~/.bashrc file but haven't had any luck as it fails. I know it fails ...
4
votes
2answers
182 views

Why are parameters to Bash's `command` and `type` optional?

Similar to Why are parameters to Bash's builtin optional?, these commands print nothing and return exit code 0 if no parameters are provided. But unlike builtin, their help output state that at least ...
4
votes
1answer
283 views

Why are parameters to Bash's builtin optional?

Running simply builtin prints nothing and returns exit code 0. This is in accordance with help builtin, which shows all parameters as optional. But why isn't this no-op an error? Is there a use case ...
12
votes
2answers
781 views

When to use a semi-colon between environment variables and a command

Can anyone explain why the semi-colon is necessary in order for the LANG to be seen as updated by bash? Doesn't work: > LANG=Ja_JP bash -c "echo $LANG" en_US Works: > LANG=Ja_JP ; bash -c ...
9
votes
2answers
5k views

Is there a way to detect null bytes (␀, NUL, \0) in sed?

Related to another question, in order to fuzzily detect binary files, is there a way to detect ␀ bytes in sed?