How do I call rename successfully from a bash script on Ubuntu? - bash

I have a bash script #!/usr/bin/env bash that is called part of a make process. This script creates a directory with the files pertinent to a realise and then tars them up. I would like to take a copy of the directory and rename some of the files to replace the version identifier with the word "latest". This will make it simple to script the acquisition of the latest file from a web-server. When I run my script, the call to rename seems to do nothing, why is that?
#!/usr/bin/env bash
DATE_NOW="$(date +'%Y%m%d')"
product_id_base="$1"
firmware_dir="${product_id_base}-full-${DATE_NOW}"
# ...rest of file ommitted to protest the innocent
# It creates and fills the ${firmware_dir} with some files that end in
# -$DATE_NOW.<extention> and I would like to rename the copies of them so that they end in
# -latest.<extention>
cp -a "./${firmware_dir}" "./${product_id_base}-full-latest"
# see what there is in pwd
cd "./${product_id_base}-full-latest"
list_output=`ls`
echo $list_output
# Things go OK until this point.
replacment="'s/${DATE_NOW}/latest/'"
rename_path=$(which rename)
echo $replacment
perl $rename_path -v $replacment *
echo $cmd
pwd
$cmd
echo "'s/-${DATE_NOW}/-latest/g'" "${product_id_base}-*"
echo $a
# check what has happened
list_output=`ls`
echo $list_output
I call the above with ./rename.sh product-id and get the expected output from ls that indicates the present working directory is the one full of files that I want renamed.
$ ./rename.sh product-id ET-PIC-v1.1.dat ET-PIC-v1.1.hex
product-id-20160321.bin product-id-20160321.dat
product-id-20160321.elf product-id-20160321.gz 's/20160321/latest/'
/home/thomasthorne/work/product-id/build/product-id-full-latest
's/-20160321/-latest/g' product-id-*
ET-PIC-v1.1.dat ET-PIC-v1.1.hex product-id-20160321.bin
product-id-20160321.dat product-id-20160321.elf product-id-20160321.gz
What I hopped to see was some renamed files. When I directly call the rename function from a terminal emulator I see the rename occur.
~/work/product-id/build/product-id-full-latest$ rename -vn
's/-20160321/-latest/g' * product-id-20160321.bin renamed as
product-id-latest.bin product-id-20160321.dat renamed as
product-id-latest.dat product-id-20160321.elf renamed as
product-id-latest.elf ...
I have tried a few variations on escaping the strings, using ` or $(), removing all the substitutions from the command line. So far nothing has worked so I must be missing something fundamental.
I have read that #!/usr/bin/env bash behaves much like #!/bin/bash so I don't think that is at play. I know that Ubuntu and Debian have different versions of the rename script to some other distributions and I am running on Ubuntu. That lead me to try calling perl /usr/bin/rename ... instead of just rename but that seems to have made no perceivable difference.

This string:
replacment="'s/${DATE_NOW}/latest/'"
will be kept exactly the same because you put it between single quotes.
Have you tried with:
replacment="s/${DATE_NOW}/latest/"
This one worked on my Ubuntu, without perl:
$ ./test_script
filename_20160321 renamed as filename_latest
filename2_20160321 renamed as filename2_latest
filename3_20160321 renamed as filename3_latest
test_script content being:
#!/bin/bash
DATE_NOW="$(date +'%Y%m%d')"
replacment="s/${DATE_NOW}/latest/"
rename -v $replacment *

Related

How to change directories in ubuntu using bash shell script? [duplicate]

I'm trying to write a small script to change the current directory to my project directory:
#!/bin/bash
cd /home/tree/projects/java
I saved this file as proj, added execute permission with chmod, and copied it to /usr/bin. When I call it by:
proj, it does nothing. What am I doing wrong?
Shell scripts are run inside a subshell, and each subshell has its own concept of what the current directory is. The cd succeeds, but as soon as the subshell exits, you're back in the interactive shell and nothing ever changed there.
One way to get around this is to use an alias instead:
alias proj="cd /home/tree/projects/java"
You're doing nothing wrong! You've changed the directory, but only within the subshell that runs the script.
You can run the script in your current process with the "dot" command:
. proj
But I'd prefer Greg's suggestion to use an alias in this simple case.
The cd in your script technically worked as it changed the directory of the shell that ran the script, but that was a separate process forked from your interactive shell.
A Posix-compatible way to solve this problem is to define a shell procedure rather than a shell-invoked command script.
jhome () {
cd /home/tree/projects/java
}
You can just type this in or put it in one of the various shell startup files.
The cd is done within the script's shell. When the script ends, that shell exits, and then you are left in the directory you were. "Source" the script, don't run it. Instead of:
./myscript.sh
do
. ./myscript.sh
(Notice the dot and space before the script name.)
To make a bash script that will cd to a select directory :
Create the script file
#!/bin/sh
# file : /scripts/cdjava
#
cd /home/askgelal/projects/java
Then create an alias in your startup file.
#!/bin/sh
# file /scripts/mastercode.sh
#
alias cdjava='. /scripts/cdjava'
I created a startup file where I dump all my aliases and custom functions.
Then I source this file into my .bashrc to have it set on each boot.
For example, create a master aliases/functions file: /scripts/mastercode.sh
(Put the alias in this file.)
Then at the end of your .bashrc file:
source /scripts/mastercode.sh
Now its easy to cd to your java directory, just type cdjava and you are there.
You can use . to execute a script in the current shell environment:
. script_name
or alternatively, its more readable but shell specific alias source:
source script_name
This avoids the subshell, and allows any variables or builtins (including cd) to affect the current shell instead.
Jeremy Ruten's idea of using a symlink triggered a thought that hasn't crossed any other answer. Use:
CDPATH=:$HOME/projects
The leading colon is important; it means that if there is a directory 'dir' in the current directory, then 'cd dir' will change to that, rather than hopping off somewhere else. With the value set as shown, you can do:
cd java
and, if there is no sub-directory called java in the current directory, then it will take you directly to $HOME/projects/java - no aliases, no scripts, no dubious execs or dot commands.
My $HOME is /Users/jleffler; my $CDPATH is:
:/Users/jleffler:/Users/jleffler/mail:/Users/jleffler/src:/Users/jleffler/src/perl:/Users/jleffler/src/sqltools:/Users/jleffler/lib:/Users/jleffler/doc:/Users/jleffler/work
Use exec bash at the end
A bash script operates on its current environment or on that of its
children, but never on its parent environment.
However, this question often gets asked because one wants to be left at a (new) bash prompt in a certain directory after execution of a bash script from within another directory.
If this is the case, simply execute a child bash instance at the end of the script:
#!/usr/bin/env bash
cd /home/tree/projects/java
echo -e '\nHit [Ctrl]+[D] to exit this child shell.'
exec bash
To return to the previous, parental bash instance, use Ctrl+D.
Update
At least with newer versions of bash, the exec on the last line is no longer required. Furthermore, the script could be made to work with whatever preferred shell by using the $SHELL environment variable. This then gives:
#!/usr/bin/env bash
cd desired/directory
echo -e '\nHit [Ctrl]+[D] to exit this child shell.'
$SHELL
I got my code to work by using. <your file name>
./<your file name> dose not work because it doesn't change your directory in the terminal it just changes the directory specific to that script.
Here is my program
#!/bin/bash
echo "Taking you to eclipse's workspace."
cd /Developer/Java/workspace
Here is my terminal
nova:~ Kael$
nova:~ Kael$ . workspace.sh
Taking you to eclipe's workspace.
nova:workspace Kael$
simply run:
cd /home/xxx/yyy && command_you_want
When you fire a shell script, it runs a new instance of that shell (/bin/bash). Thus, your script just fires up a shell, changes the directory and exits. Put another way, cd (and other such commands) within a shell script do not affect nor have access to the shell from which they were launched.
You can do following:
#!/bin/bash
cd /your/project/directory
# start another shell and replacing the current
exec /bin/bash
EDIT: This could be 'dotted' as well, to prevent creation of subsequent shells.
Example:
. ./previous_script (with or without the first line)
On my particular case i needed too many times to change for the same directory.
So on my .bashrc (I use ubuntu) i've added the
1 -
$ nano ~./bashrc
function switchp
{
cd /home/tree/projects/$1
}
2-
$ source ~/.bashrc
3 -
$ switchp java
Directly it will do: cd /home/tree/projects/java
Hope that helps!
It only changes the directory for the script itself, while your current directory stays the same.
You might want to use a symbolic link instead. It allows you to make a "shortcut" to a file or directory, so you'd only have to type something like cd my-project.
You can combine Adam & Greg's alias and dot approaches to make something that can be more dynamic—
alias project=". project"
Now running the project alias will execute the project script in the current shell as opposed to the subshell.
You can combine an alias and a script,
alias proj="cd \`/usr/bin/proj !*\`"
provided that the script echos the destination path. Note that those are backticks surrounding the script name.
For example, your script could be
#!/bin/bash
echo /home/askgelal/projects/java/$1
The advantage with this technique is that the script could take any number of command line parameters and emit different destinations calculated by possibly complex logic.
to navigate directories quicky, there's $CDPATH, cdargs, and ways to generate aliases automatically
http://jackndempsey.blogspot.com/2008/07/cdargs.html
http://muness.blogspot.com/2008/06/lazy-bash-cd-aliaes.html
https://web.archive.org/web/1/http://articles.techrepublic%2ecom%2ecom/5100-10878_11-5827311.html
In your ~/.bash_profile file. add the next function
move_me() {
cd ~/path/to/dest
}
Restart terminal and you can type
move_me
and you will be moved to the destination folder.
You can use the operator && :
cd myDirectory && ls
While sourcing the script you want to run is one solution, you should be aware that this script then can directly modify the environment of your current shell. Also it is not possible to pass arguments anymore.
Another way to do, is to implement your script as a function in bash.
function cdbm() {
cd whereever_you_want_to_go
echo "Arguments to the functions were $1, $2, ..."
}
This technique is used by autojump: http://github.com/joelthelion/autojump/wiki to provide you with learning shell directory bookmarks.
You can create a function like below in your .bash_profile and it will work smoothly.
The following function takes an optional parameter which is a project.
For example, you can just run
cdproj
or
cdproj project_name
Here is the function definition.
cdproj(){
dir=/Users/yourname/projects
if [ "$1" ]; then
cd "${dir}/${1}"
else
cd "${dir}"
fi
}
Dont forget to source your .bash_profile
This should do what you want. Change to the directory of interest (from within the script), and then spawn a new bash shell.
#!/bin/bash
# saved as mov_dir.sh
cd ~/mt/v3/rt_linux-rt-tools/
bash
If you run this, it will take you to the directory of interest and when you exit it it will bring you back to the original place.
root#intel-corei7-64:~# ./mov_dir.sh
root#intel-corei7-64:~/mt/v3/rt_linux-rt-tools# exit
root#intel-corei7-64:~#
This will even take you to back to your original directory when you exit (CTRL+d)
I did the following:
create a file called case
paste the following in the file:
#!/bin/sh
cd /home/"$1"
save it and then:
chmod +x case
I also created an alias in my .bashrc:
alias disk='cd /home/; . case'
now when I type:
case 12345
essentially I am typing:
cd /home/12345
You can type any folder after 'case':
case 12
case 15
case 17
which is like typing:
cd /home/12
cd /home/15
cd /home/17
respectively
In my case the path is much longer - these guys summed it up with the ~ info earlier.
As explained on the other answers, you have changed the directory, but only within the sub-shell that runs the script. this does not impact the parent shell.
One solution is to use bash functions instead of a bash script (sh); by placing your bash script code into a function. That makes the function available as a command and then, this will be executed without a child process and thus any cd command will impact the caller shell.
Bash functions :
One feature of the bash profile is to store custom functions that can be run in the terminal or in bash scripts the same way you run application/commands this also could be used as a shortcut for long commands.
To make your function efficient system widely you will need to copy your function at the end of several files
/home/user/.bashrc
/home/user/.bash_profile
/root/.bashrc
/root/.bash_profile
You can sudo kwrite /home/user/.bashrc /home/user/.bash_profile /root/.bashrc /root/.bash_profile to edit/create those files quickly
Howto :
Copy your bash script code inside a new function at the end of your bash's profile file and restart your terminal, you can then run cdd or whatever the function you wrote.
Script Example
Making shortcut to cd .. with cdd
cdd() {
cd ..
}
ls shortcut
ll() {
ls -l -h
}
ls shortcut
lll() {
ls -l -h -a
}
If you are using fish as your shell, the best solution is to create a function. As an example, given the original question, you could copy the 4 lines below and paste them into your fish command line:
function proj
cd /home/tree/projects/java
end
funcsave proj
This will create the function and save it for use later. If your project changes, just repeat the process using the new path.
If you prefer, you can manually add the function file by doing the following:
nano ~/.config/fish/functions/proj.fish
and enter the text:
function proj
cd /home/tree/projects/java
end
and finally press ctrl+x to exit and y followed by return to save your changes.
(NOTE: the first method of using funcsave creates the proj.fish file for you).
You need no script, only set the correct option and create an environment variable.
shopt -s cdable_vars
in your ~/.bashrc allows to cd to the content of environment variables.
Create such an environment variable:
export myjava="/home/tree/projects/java"
and you can use:
cd myjava
Other alternatives.
Note the discussion How do I set the working directory of the parent process?
It contains some hackish answers, e.g.
https://stackoverflow.com/a/2375174/755804 (changing the parent process directory via gdb, don't do this) and https://stackoverflow.com/a/51985735/755804 (the command tailcd that injects cd dirname to the input stream of the parent process; well, ideally it should be a part of bash rather than a hack)
It is an old question, but I am really surprised I don't see this trick here
Instead of using cd you can use
export PWD=the/path/you/want
No need to create subshells or use aliases.
Note that it is your responsibility to make sure the/path/you/want exists.
I have to work in tcsh, and I know this is not an elegant solution, but for example, if I had to change folders to a path where one word is different, the whole thing can be done in the alias
a alias_name 'set a = `pwd`; set b = `echo $a | replace "Trees" "Tests"` ; cd $b'
If the path is always fixed, the just
a alias_name2 'cd path/you/always/need'
should work
In the line above, the new folder path is set
This combines the answer by Serge with an unrelated answer by David. It changes the directory, and then instead of forcing a bash shell, it launches the user's default shell. It however requires both getent and /etc/passwd to detect the default shell.
#!/usr/bin/env bash
cd desired/directory
USER_SHELL=$(getent passwd <USER> | cut -d : -f 7)
$USER_SHELL
Of course this still has the same deficiency of creating a nested shell.

Batch renaming files in OSX terminal

I'm trying to rename files e.g. screen-0001.tif to 0001.tif using the approach in this SO question:
for file in *.tif
do
echo mv "$file" "${screen-/file}"
done
fails to change anything. Grateful for an idea where I'm going wrong.
The easier, IMHO, way to do this is using Perl's rename script. Here I am using it with --dry-run so it just tells you what it would do, rather than actually doing anything. You would just remove --dry-run if/when you are happy with the command:
rename --dry-run 's/screen-//' *tif
'screen-001.tif' would be renamed to '001.tif'
'screen-002.tif' would be renamed to '002.tif'
'screen-003.tif' would be renamed to '003.tif'
'screen-004.tif' would be renamed to '004.tif'
It has the added benefit that it will not overwrite any files that happen to come out to the same name. So, if you had files:
screen-001.tif
0screen-01.tif
And you did this, you would get:
rename 's/screen-//' *tif
'screen-001.tif' not renamed: '001.tif' already exists
rename is easily installed using Homebrew, using:
brew install rename
Two things:
You're echoing the commands and not actually executing them. I will do this when I do massive renames just to make sure that the command works correctly. I can redirect the output to a file, and then use that file as a shell script.
The substitution is wrong. There are two ways:
Left most filter ${file#screen-}.
Substitution: ${file/screen/}
The name of the environment variable always goes first. Then the pattern type, then the pattern
Here's how I would do this:
$ for file in *.tif
> do
> echo "mv '$file' '${file#screen-}'"
> done | tee mymove.sh # Build a shell script
$ vi mymove.sh # Examine the shell script and make sure everything is correct
$ bash mymove.sh # If all is good, execute the shell script.

Rsync copies too many directories being executed via bash script

Originally I would like to sync directory (with all files and subdirectories) given in parameter in bash script.
I found this post: How can I recursively copy a directory into another and replace only the files that have not changed? which explains how to use rsync in similar case.
My bash script is quite simple and listed below:
#!/bin/bash
echo -e "Type the project to be deployed: \c "
read project
echo -e "* Deploying: $project *"
echo -e "Sync: /var/repo/released/$project"
echo -e " /var/www/released/$project"
rsync -pr /var/repo/released/$project /var/www/released/$project
As a result it copies everything within /released (there are many directories in there, let's say -projects-).
I would like to copy (sync) only project given in parameter.
Could you please advice how to do this?
When you call the script without an argument (which most likely is what you're doing since you interactively read the project name into the variable $project), the positional parameter $1 remains empty. Therefore the script will rsync the entire content of /var/repo/released/.
You need to replace $1 with $project in your script. Also, I'd recommend to put double quotes around the paths to avoid problems due to spaces in a directory name.
rsync -pr "/var/repo/released/$project" "/var/www/released/$project"

"Escaping" nightmare

I have been trying to put the following into a bash script:
scp /cygdrive/c/Program\ Files\ \(x86\)/Spiceworks/data/configurations/LA_$(date +%F)-firewall-5520 "sf-mlawler#10.21.1.212:/home/sf-mlawler/SBOX_Automation/SBOX_Dumps/08\ -\ Security/Firewalls"
...which works as expected via command line.
When I try to place it in a script, I'm obviously going to have to double escape the spaces, anything else? I'm unable to have success with the multitude of variations I've tried.
I would think:
scp /cygdrive/c/Program\\ Files\\ \(x86\)/Spiceworks/data/configurations/LA_\$(date\ +%F)-firewall-5520 "sf-mlawler#10.21.1.212:/home/sf-mlawler/SBOX_Automation/SBOX_Dumps/08\\ \\-\\ Security/Firewalls"
...would work, but it doesn't. Any suggestions, before I go grey and bald? Thanks
I wont waste the space with all variations I've tried, but I will say I have tried escaping almost everything and basically nothing and many in between with no success. When I receive a "No such file or Directory" I obviously escape until the file actually resolves, but even when I do not get a path error, the command is not successfully completing.
I do understand this is quite a specific case, but I imagine it will help others in the future: escaping spaces, in a bash script, using embedded expect (I have tested with a #!/bin/bash shebang and the embedded expect using expect -c ' .... ' as well as #!/usr/bin/expect using a simple spawn scp command with no change.
EDIT (Based on responses):
I should have mentioned I have tried quoting it...
Quoting the first (host) part gives me the error
can't read "(date +%F)": no such variable
while executing
"spawn scp "/cygdrive/c/Program Files (x86)/Spiceworks/data/configurations/LA_$(date +%F)-firewall-5520" "sf-mlawler#10.21.1.212:/home/sf-mlawler/SBOX_..."
...it is not a variable, it is a function giving me the current date in the format year-month-day
Quoting the destination section without escaping anything gives me the error
scp: ambiguous target
The same command that worked on your bash shell should work the same in your bash script. You shouldn't and cannot escape it twice.
If it doesn't work, make sure you're testing the script from the same terminal, ensure that the script contents and your command is identical, then paste the output from your terminal when you do:
$ scp /cygdrive/c/Program\ Files\ \(x86\)/Spiceworks/data/configurations/LA_$(date +%F)-firewall-5520 "sf-mlawler#10.21.1.212:/home/sf-mlawler/SBOX_Automation/SBOX_Dumps/08\ -\ Security/Firewalls"
(successful scp output here)
$ cat testscript
(testscript contents here, should be identical to above scp command)
$ bash testscript
(unsuccessful script/scp output here)
Just stick it in quotes and stop hitting yourself, as #that_other_guy said, you cannot, and shouldn't try and escape twice, wherever you got that idea, disregard it as a source of information. (my guess is it came from "thin air")
scp "/cygdrive/c/Program Files (x86)/Spiceworks/data/configurations/LA_$(date +%F)-firewall-5520" "sf-mlawler#10.21.1.212:/home/sf-mlawler/SBOX_Automation/SBOX_Dumps/08 - Security/Firewalls"
You could even give yourself some helpers:
export PROGFILESx86="/cygdrive/c/Program Files (x86)"
export SPICEWORKS_CONFIGS="${PROGFILESx86}/Spiceworks/data/configurations"
(add them to .bashrc, exec it.) and then do:
scp "${SPICEWORKS_CONFIGS}/LA_$(date +%F)-firewall-5520" "sf-mlawler#10.21.1.212:/home/sf-mlawler/SBOX_Automation/SBOX_Dumps/08 - Security/Firewalls"
I'd also be concerned the the files you are attempting to scp actually exist, wrap it up in a condition to verify they're there, it only makes sense when you're auto-generating a filename.
firewall_config="${SPICEWORKS_CONFIGS}/LA_$(date +%F)-firewall-5520"
if [ -e "${firewall_config}" ]
then
scp "${firewall_config}" "sf-mlawler#10.21.1.212:/home/sf-mlawler/SBOX_Automation/SBOX_Dumps/08 - Security/Firewalls"
else
echo "File doesn't exist: ${firewall_config}"
fi
Update:
Since you've updated your question, it's obviously the date call that's giving you the biggest problem, again, indirection saves you doing bizarre escape-char-yoga, just get the result into a var and use that.
fw_date=$(date +%F)
firewall_config="${SPICEWORKS_CONFIGS}/LA_${fw_date}-firewall-5520"

Why can't I change directories using "cd" in a script?

I'm trying to write a small script to change the current directory to my project directory:
#!/bin/bash
cd /home/tree/projects/java
I saved this file as proj, added execute permission with chmod, and copied it to /usr/bin. When I call it by:
proj, it does nothing. What am I doing wrong?
Shell scripts are run inside a subshell, and each subshell has its own concept of what the current directory is. The cd succeeds, but as soon as the subshell exits, you're back in the interactive shell and nothing ever changed there.
One way to get around this is to use an alias instead:
alias proj="cd /home/tree/projects/java"
You're doing nothing wrong! You've changed the directory, but only within the subshell that runs the script.
You can run the script in your current process with the "dot" command:
. proj
But I'd prefer Greg's suggestion to use an alias in this simple case.
The cd in your script technically worked as it changed the directory of the shell that ran the script, but that was a separate process forked from your interactive shell.
A Posix-compatible way to solve this problem is to define a shell procedure rather than a shell-invoked command script.
jhome () {
cd /home/tree/projects/java
}
You can just type this in or put it in one of the various shell startup files.
The cd is done within the script's shell. When the script ends, that shell exits, and then you are left in the directory you were. "Source" the script, don't run it. Instead of:
./myscript.sh
do
. ./myscript.sh
(Notice the dot and space before the script name.)
To make a bash script that will cd to a select directory :
Create the script file
#!/bin/sh
# file : /scripts/cdjava
#
cd /home/askgelal/projects/java
Then create an alias in your startup file.
#!/bin/sh
# file /scripts/mastercode.sh
#
alias cdjava='. /scripts/cdjava'
I created a startup file where I dump all my aliases and custom functions.
Then I source this file into my .bashrc to have it set on each boot.
For example, create a master aliases/functions file: /scripts/mastercode.sh
(Put the alias in this file.)
Then at the end of your .bashrc file:
source /scripts/mastercode.sh
Now its easy to cd to your java directory, just type cdjava and you are there.
You can use . to execute a script in the current shell environment:
. script_name
or alternatively, its more readable but shell specific alias source:
source script_name
This avoids the subshell, and allows any variables or builtins (including cd) to affect the current shell instead.
Jeremy Ruten's idea of using a symlink triggered a thought that hasn't crossed any other answer. Use:
CDPATH=:$HOME/projects
The leading colon is important; it means that if there is a directory 'dir' in the current directory, then 'cd dir' will change to that, rather than hopping off somewhere else. With the value set as shown, you can do:
cd java
and, if there is no sub-directory called java in the current directory, then it will take you directly to $HOME/projects/java - no aliases, no scripts, no dubious execs or dot commands.
My $HOME is /Users/jleffler; my $CDPATH is:
:/Users/jleffler:/Users/jleffler/mail:/Users/jleffler/src:/Users/jleffler/src/perl:/Users/jleffler/src/sqltools:/Users/jleffler/lib:/Users/jleffler/doc:/Users/jleffler/work
Use exec bash at the end
A bash script operates on its current environment or on that of its
children, but never on its parent environment.
However, this question often gets asked because one wants to be left at a (new) bash prompt in a certain directory after execution of a bash script from within another directory.
If this is the case, simply execute a child bash instance at the end of the script:
#!/usr/bin/env bash
cd /home/tree/projects/java
echo -e '\nHit [Ctrl]+[D] to exit this child shell.'
exec bash
To return to the previous, parental bash instance, use Ctrl+D.
Update
At least with newer versions of bash, the exec on the last line is no longer required. Furthermore, the script could be made to work with whatever preferred shell by using the $SHELL environment variable. This then gives:
#!/usr/bin/env bash
cd desired/directory
echo -e '\nHit [Ctrl]+[D] to exit this child shell.'
$SHELL
I got my code to work by using. <your file name>
./<your file name> dose not work because it doesn't change your directory in the terminal it just changes the directory specific to that script.
Here is my program
#!/bin/bash
echo "Taking you to eclipse's workspace."
cd /Developer/Java/workspace
Here is my terminal
nova:~ Kael$
nova:~ Kael$ . workspace.sh
Taking you to eclipe's workspace.
nova:workspace Kael$
simply run:
cd /home/xxx/yyy && command_you_want
When you fire a shell script, it runs a new instance of that shell (/bin/bash). Thus, your script just fires up a shell, changes the directory and exits. Put another way, cd (and other such commands) within a shell script do not affect nor have access to the shell from which they were launched.
You can do following:
#!/bin/bash
cd /your/project/directory
# start another shell and replacing the current
exec /bin/bash
EDIT: This could be 'dotted' as well, to prevent creation of subsequent shells.
Example:
. ./previous_script (with or without the first line)
On my particular case i needed too many times to change for the same directory.
So on my .bashrc (I use ubuntu) i've added the
1 -
$ nano ~./bashrc
function switchp
{
cd /home/tree/projects/$1
}
2-
$ source ~/.bashrc
3 -
$ switchp java
Directly it will do: cd /home/tree/projects/java
Hope that helps!
It only changes the directory for the script itself, while your current directory stays the same.
You might want to use a symbolic link instead. It allows you to make a "shortcut" to a file or directory, so you'd only have to type something like cd my-project.
You can combine Adam & Greg's alias and dot approaches to make something that can be more dynamic—
alias project=". project"
Now running the project alias will execute the project script in the current shell as opposed to the subshell.
You can combine an alias and a script,
alias proj="cd \`/usr/bin/proj !*\`"
provided that the script echos the destination path. Note that those are backticks surrounding the script name.
For example, your script could be
#!/bin/bash
echo /home/askgelal/projects/java/$1
The advantage with this technique is that the script could take any number of command line parameters and emit different destinations calculated by possibly complex logic.
to navigate directories quicky, there's $CDPATH, cdargs, and ways to generate aliases automatically
http://jackndempsey.blogspot.com/2008/07/cdargs.html
http://muness.blogspot.com/2008/06/lazy-bash-cd-aliaes.html
https://web.archive.org/web/1/http://articles.techrepublic%2ecom%2ecom/5100-10878_11-5827311.html
In your ~/.bash_profile file. add the next function
move_me() {
cd ~/path/to/dest
}
Restart terminal and you can type
move_me
and you will be moved to the destination folder.
You can use the operator && :
cd myDirectory && ls
While sourcing the script you want to run is one solution, you should be aware that this script then can directly modify the environment of your current shell. Also it is not possible to pass arguments anymore.
Another way to do, is to implement your script as a function in bash.
function cdbm() {
cd whereever_you_want_to_go
echo "Arguments to the functions were $1, $2, ..."
}
This technique is used by autojump: http://github.com/joelthelion/autojump/wiki to provide you with learning shell directory bookmarks.
You can create a function like below in your .bash_profile and it will work smoothly.
The following function takes an optional parameter which is a project.
For example, you can just run
cdproj
or
cdproj project_name
Here is the function definition.
cdproj(){
dir=/Users/yourname/projects
if [ "$1" ]; then
cd "${dir}/${1}"
else
cd "${dir}"
fi
}
Dont forget to source your .bash_profile
This should do what you want. Change to the directory of interest (from within the script), and then spawn a new bash shell.
#!/bin/bash
# saved as mov_dir.sh
cd ~/mt/v3/rt_linux-rt-tools/
bash
If you run this, it will take you to the directory of interest and when you exit it it will bring you back to the original place.
root#intel-corei7-64:~# ./mov_dir.sh
root#intel-corei7-64:~/mt/v3/rt_linux-rt-tools# exit
root#intel-corei7-64:~#
This will even take you to back to your original directory when you exit (CTRL+d)
I did the following:
create a file called case
paste the following in the file:
#!/bin/sh
cd /home/"$1"
save it and then:
chmod +x case
I also created an alias in my .bashrc:
alias disk='cd /home/; . case'
now when I type:
case 12345
essentially I am typing:
cd /home/12345
You can type any folder after 'case':
case 12
case 15
case 17
which is like typing:
cd /home/12
cd /home/15
cd /home/17
respectively
In my case the path is much longer - these guys summed it up with the ~ info earlier.
As explained on the other answers, you have changed the directory, but only within the sub-shell that runs the script. this does not impact the parent shell.
One solution is to use bash functions instead of a bash script (sh); by placing your bash script code into a function. That makes the function available as a command and then, this will be executed without a child process and thus any cd command will impact the caller shell.
Bash functions :
One feature of the bash profile is to store custom functions that can be run in the terminal or in bash scripts the same way you run application/commands this also could be used as a shortcut for long commands.
To make your function efficient system widely you will need to copy your function at the end of several files
/home/user/.bashrc
/home/user/.bash_profile
/root/.bashrc
/root/.bash_profile
You can sudo kwrite /home/user/.bashrc /home/user/.bash_profile /root/.bashrc /root/.bash_profile to edit/create those files quickly
Howto :
Copy your bash script code inside a new function at the end of your bash's profile file and restart your terminal, you can then run cdd or whatever the function you wrote.
Script Example
Making shortcut to cd .. with cdd
cdd() {
cd ..
}
ls shortcut
ll() {
ls -l -h
}
ls shortcut
lll() {
ls -l -h -a
}
If you are using fish as your shell, the best solution is to create a function. As an example, given the original question, you could copy the 4 lines below and paste them into your fish command line:
function proj
cd /home/tree/projects/java
end
funcsave proj
This will create the function and save it for use later. If your project changes, just repeat the process using the new path.
If you prefer, you can manually add the function file by doing the following:
nano ~/.config/fish/functions/proj.fish
and enter the text:
function proj
cd /home/tree/projects/java
end
and finally press ctrl+x to exit and y followed by return to save your changes.
(NOTE: the first method of using funcsave creates the proj.fish file for you).
You need no script, only set the correct option and create an environment variable.
shopt -s cdable_vars
in your ~/.bashrc allows to cd to the content of environment variables.
Create such an environment variable:
export myjava="/home/tree/projects/java"
and you can use:
cd myjava
Other alternatives.
Note the discussion How do I set the working directory of the parent process?
It contains some hackish answers, e.g.
https://stackoverflow.com/a/2375174/755804 (changing the parent process directory via gdb, don't do this) and https://stackoverflow.com/a/51985735/755804 (the command tailcd that injects cd dirname to the input stream of the parent process; well, ideally it should be a part of bash rather than a hack)
It is an old question, but I am really surprised I don't see this trick here
Instead of using cd you can use
export PWD=the/path/you/want
No need to create subshells or use aliases.
Note that it is your responsibility to make sure the/path/you/want exists.
I have to work in tcsh, and I know this is not an elegant solution, but for example, if I had to change folders to a path where one word is different, the whole thing can be done in the alias
a alias_name 'set a = `pwd`; set b = `echo $a | replace "Trees" "Tests"` ; cd $b'
If the path is always fixed, the just
a alias_name2 'cd path/you/always/need'
should work
In the line above, the new folder path is set
This combines the answer by Serge with an unrelated answer by David. It changes the directory, and then instead of forcing a bash shell, it launches the user's default shell. It however requires both getent and /etc/passwd to detect the default shell.
#!/usr/bin/env bash
cd desired/directory
USER_SHELL=$(getent passwd <USER> | cut -d : -f 7)
$USER_SHELL
Of course this still has the same deficiency of creating a nested shell.

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