The shell is unix's command-line interface. You can type commands in a shell interactively, or write scripts to automate tasks. Use this tag for questions applying to /bin/sh and most compatible shells (ash, bash, ksh, zsh, …).

learn more… | top users | synonyms (1)

4
votes
4answers
2k views

How to add system alias?

I have this alias in my .zshrc: alias grim='gvim --remote' But this is not seen from ranger file manager, I believe that ranger runs a 'generic' shell skipping my .zshrc. I want to make this alias ...
-1
votes
1answer
128 views

Why do many CLI apps take a single “--” argument? [duplicate]

Possible Duplicate: What does “--” (double-dash) mean? There are many command line tools that take a single "--" argument. For example: gem install mysql -- ...
3
votes
3answers
2k views

Bash while loop and reading from pipe

I have a Windows command-line program that I'm running in a Bash script in Ubuntu via wine. The Bash script basically looks like this: wine myprogram.exe | while read line do # Process line done ...
3
votes
3answers
3k views

Shell script to become root

How can we write a shell script to become root? That is I donot want to input the password at prompt it should be within the script itself. I was trying to make but failed to do so.Is it possible, if ...
5
votes
1answer
2k views

Can I refresh my shell within a shell script?

Very new to Bash scripting... I am trying to setup a script that starts with a minimal CentOS 6 install and provisions it for Ruby development. #!/bin/bash # Add PostgreSQL Repo rpm -i ...
3
votes
1answer
1k views

Parameretrize file descriptor number to open a tcp socket in shell script

I'm tried to parameretrize in a variable the file descriptor number to open a tcp socket using exec command but it failed. Only work correctly when file descriptor number is a constant. In the next ...
7
votes
3answers
2k views

How to go back n levels of directories from the command line?

For example, I do the following cds in succession- cd /tmp cd /home/admin cd /root/ cd /some_other/directory Now I am in /some_other/directory. Now, is there anyway to go back to /tmp, the ...
103
votes
6answers
13k views

How to run a command without hitting Enter Key?

Accidently I mapped Enter via xkbset to Pointer_button2. Now every time I hit Enter some gibberish text appears. I thought of a workaround involving remapping it back, but that means I will have to ...
20
votes
2answers
36k views

Bash: How to read one line at a time from output of a command?

I am trying to read the output of a command in bash using a while loop. while read -r line do echo "$line" done <<< $(find . -type f) The output I got ranveer@ranveer:~/tmp$ bash ...
3
votes
1answer
178 views

How to expand a substring of a command?

I would like to know what a command would look like if I entered a substring of this command. I'm not interested in the result, but in the history expansion. The purpose of this is to show in an ...
3
votes
3answers
2k views

Solarized colors in st (simple terminal)

I want to use st with solarized colors like I can with urxvt (of course this is done via .Xresources, in st the colors are defined in a header file). I've tried to put the colors in st's config file ...
4
votes
2answers
600 views

Function caller positional parameters

I need to read and write the positional parameters $@ of a function's caller. The Bash man page says that: A shell function is an object that is called like a simple command and executes a ...
31
votes
3answers
26k views

How to combine 2 -name conditions in find?

I would like to search for files that would not match 2 -name conditions. I can do it like so : find /media/d/ -type f -size +50M ! -name "*deb" ! -name "*vmdk" and this will yield proper result ...
34
votes
2answers
19k views

What is the difference between interactive shells, login shells, non-login shell and their use cases? [duplicate]

Possible Duplicate: Difference between Login Shell and Non-Login Shell? I have been looking at /etc/profile. bash.bashrc to see how they are run, and notice that some are executed by ...
6
votes
2answers
21k views

How can I detect that no options were passed with getopts?

I have this code - #getoptDemo.sh usage() { echo "usage: <command> options:<w|l|h>" } while getopts wlh: option do case $option in (w) name='1';; ...
7
votes
3answers
6k views

Test command in unix doesn't print an output

When I type this in the terminal test 4 -lt 6 I don't get any output. Why not? I need that 0 or 1
6
votes
3answers
2k views

Equivalent of date --reference in Solaris

The GNU implementation of the date command has a nice feature to show the date of the last modification of a reference file. Then using the +FORMAT parameter it's easy to get the date in any format, ...
1
vote
5answers
1k views

Run a command on all the files in a directory tree and put the output into a variable

I want to run this bash command : #!/bin/bash rep="*" for f in `ls -R`$rep; do d='git log '$f'| wc -l' c=$d echo $c done how to excute a command git log myFile | wc -l from bash ? ps : this ...
1
vote
2answers
657 views

List info about files/directories with spaces

I am trying to use ls to get information about files and directories. My current command fails to properly get the name whenever a file/directory has a space. I am using this to list all ...
1
vote
2answers
228 views

Complicated variable content failed to get into sed

The first line is variable ann hold quite complicated value. The reason I use the second line is because I don't want to change anything in the third line col1content. To change replacement, I just ...
1
vote
3answers
172 views

Restructuring directories into a hierarchy

I have the following type of folder structure containing thousands of folders. The folder names are as such with different names etc .test .test.subfolder .test.subfolder.subsubfolder .folder ...
10
votes
5answers
10k views

How do I perform an action on all files with a specific extension in subfolders in an elegant way?

My current best bet is: for i in $(find . -name *.jpg); do echo $i; done Problem: does not handle spaces in filenames. Note: I would also love a graphical way of doing this, such as the "tree" ...
0
votes
2answers
4k views

print command not found

From the korn shell, I keep getting print command not found. When I run print from the shell, it says the same thing. How would I go about fixing this? printf works fine, but for some reason print is ...
9
votes
3answers
10k views

Using OR patterns in shell wildcards

Contents of my dir are $ ls -lrt total 0 -rw-r--r-- 1 user1 admin 19 Oct 8 12:31 night.txt -rw-r--r-- 1 user1 admin 19 Oct 8 12:31 noon.txt -rw-r--r-- 1 user1 admin 38 Oct 8 12:31 day.txt I ...
4
votes
2answers
1k views

List files created on Sundays

How do I list/find all the files created on Sundays or Mondays? How do I use the date parameter to display them? Something like : ls -f date + %a or find -type f | date +%A or find -type f ...
5
votes
4answers
19k views

Calculate variable, and output it to another variable

The only calculator I know is bc. I want to add 1 to a variable, and output to another variable. I got the nextnum variable from counting string in a file: nextnum=`grep -o stringtocount ...
0
votes
2answers
20k views

How to change the working directory of invoking shell using a script? [duplicate]

Possible Duplicate: changing current working dir with a script I am trying to create few scripts that would change the working directory of the main shell/terminal. Not able to do so. I ...
5
votes
3answers
14k views

Find files which are created a certain time after or before a particular file was created

I need a shell script which finds files which are created 1 hour before or 1 hour after a particular file (test.txt) was created. If I go with find -newer, that means I'd have to create a temporary ...
26
votes
6answers
3k views

Why can't I redirect a path name output from one command to “cd”?

I am trying to get cd to accept a directory name redirected to it from another command. Neither of these methods work: $ echo $HOME | cd $ echo $HOME | xargs cd This does work: $ cd $(echo $HOME) ...
2
votes
6answers
9k views

ls: Do not show directories that match same pattern in wildcard searches, only files

Supposing I have something like the following, a typical business PC situation: drwxr-xr-x 1 whatever whoever 3 Oct 3 16:40 invoices2009 drwxr-xr-x 1 whatever whoever 4 Oct 3 16:40 ...
22
votes
2answers
18k views

/dev/tcp listen instead of nc listen

With a netcat listener like: nc -l <port> < ~/.bashrc I can grab my .bashrc on a new machine (doesn't have nc or LDAP) with: cat < /dev/tcp/<ip>/<port> > ~/.bashrc My ...
9
votes
3answers
330 views

When was process substitution first introduced?

I'm curios to know how long process substitution has been around. What shell first had it? When did it get added to other shells?
28
votes
3answers
12k views

Recursive glob?

I'd like to write something like this: $ ls **.py in order to get all .py filenames, recursively walking a directory hierarchy. Even if there are .py files to find, the shell (bash) gives this ...
2
votes
1answer
393 views

Why does newgrp change my PS1 and how to prevent it?

I have a customized PS1 to show several parameters. When I switch to a different group using newgrp, it switched my PS1 to default ($) and that is annoying. The default remains even when I switch ...
2
votes
1answer
1k views

Bash overwrites the first line, PS1 bash prompt

I have played around with PS1 and PROMPT_COMMAND in bash to create a zsh-style right side prompt. I have a solution who almost works. The problem is that if I write a long line of input, the second ...
5
votes
1answer
1k views

How does sh -e interact with &?

I'm using sh (dash) on Ubuntu (lucid) and the manpage has this to say about -e: -e errexit If not interactive, exit immediately if any untested command fails. ...
1
vote
1answer
202 views

Can we use history file for auditing purpose

We have a common testing environment on AIX for all 15-20 persons. There might be chances that somebody deleted the files mistakenly. In such scenarios, it is very difficult to know who deleted files ...
4
votes
4answers
426 views

Follow a moved file to its destination directory

Is there a way to move a file from a directory to another and then cd into the latter in one command? Something like mv /a/file /another/dir && cd _ but without typing second time the ...
3
votes
3answers
190 views

How can I identify the variant of Unix/Linux from a shell? [duplicate]

Possible Duplicate: How can I get distribution name and version number in a simple shell script? Given a shell, how can I identify the variant of Unix/Linux that is running on a remote ...
3
votes
2answers
735 views

how to grep for c:\

I'm using cygwin's grep to find all instances of hardcoded paths on c drive. doing: grep -r "c:\\" . gives grep: trailing backslash Does anybody know how I can do this?
12
votes
2answers
3k views

Interactively deleting files from a list

I'd like to remove a list of files and be asked for confirmation. The list is in the list.txt file. Why the following command doesn't work properly? while read i; do rm -i $i; done < list.txt ...
0
votes
1answer
299 views

Change Directory and List Files [duplicate]

Possible Duplicate: Make cd automatically ls I think that it would be very useful to have a unix utility that combines 'cd' and 'ls' so that when you change your directory, it automatically ...
3
votes
1answer
12k views

What killed tty main process suddenly?

I'm doing some stress testing of a piece of software that can run shell commands. Periodically, the system logs me out during stress testing. My record of the commands that triggered this always ...
0
votes
1answer
4k views

Unique lines based on the first field

How can you find unique lines or duplicate lines in a file based on the content of the first field, or the first n characters ? The uniq command on OS X lacks the -w switch that is available under ...
1
vote
2answers
3k views

Reserved characters in file names

I was under the impression that the only character not allowed in file names was /, but I don't seem to be able to create a file whose name contains characters such as *, \, ", :, |, < or > ...
3
votes
1answer
142 views

the return built-in

According to the Open Group, [t]he return utility shall cause the shell to stop executing the current function or dot script. If the shell is not currently executing a function or dot script, ...
2
votes
2answers
413 views

Unzip to location

I am using unzip through putty and it works ok. However, using the same command through a .NET C# SSH library (Renci.SshNet) gives different results. SshClient s = new SshClient("ssh_host", ...
1
vote
3answers
4k views

How to know if a file has been written completely?

I have shell script which waits for some files to arrive from remote machine, when it arrives, it cats them to a new file. For that I am using a while loop,like following: while true do if [ ...
1
vote
2answers
903 views

Auto-expansion problem with array elements containing an '*' (asterisk)

I'm trying to write me a find script that should later be able to read a list of directories to be excluded from an external file. Whilst I can accomplish that part myself, it's the annoying array ...
3
votes
3answers
1k views

Is there a way to get *actual* (uninterpreted) shell arguments in a function or script?

I have a function posix that I use in the Git bash shell on Windows to transform DOS-style paths to normal Unix-style paths. Since DOS-style paths use a backslash as separator, I have to quote the ...