I have to work within three main directories under the root filesystem - home/username, project, and scratch. I want my shell prompt to display which of these top level directories i am in.
Here is what I am trying to do:
top_level_dir ()
{
if [[ "${PWD}" == *home* ]]
then
echo "home";
elif [[ "${PWD}" == *scratch* ]]
then
echo "scratch";
elif [[ "${PWD}" == *project* ]]
then
echo "project";
fi
}
Then, I export PS1 as:
export PS1='$(top_level_dir) : '
Unfortunately this is not working as I want. I get home : for my prompt when I am in my home directory, but if I switch to scratch or projects then the prompt does not change. I do not understand bash scripting very well so I would appreciate any help to correct my code.
You can hook into cd to change the prompt every time you are changing the working directory. I've asked myself often how to hook into cd but I think that I now found a solution. What about adding this to your ~/.bashrc?:
#
# Wrapper function that is called if cd is invoked
# by the current shell
#
function cd {
# call builtin cd. change to the new directory
builtin cd $#
# call a hook function that can use the new working directory
# to decide what to do
color_prompt
}
#
# Changes the color of the prompt depending
# on the current working directory
#
function color_prompt {
pwd=$(pwd)
if [[ "$pwd/" =~ ^/home/ ]] ; then
PS1='\[\033[01;32m\]\u#\h:\w\[\033[00m\]\$ '
elif [[ "$pwd/" =~ ^/etc/ ]] ; then
PS1='\[\033[01;34m\]\u#\h:\w\[\033[00m\]\$ '
elif [[ "$pwd/" =~ ^/tmp/ ]] ; then
PS1='\[\033[01;33m\]\u#\h:\w\[\033[00m\]\$ '
else
PS1='\u#\h:\w\\$ '
fi
export PS1
}
# checking directory and setting prompt on shell startup
color_prompt
Please try this method instead and tell us how it works e.g. how your prompt changes in your home directory, your project or scratch directory, and other directories besides those. Tell us what error messages you see as well. The problem lies within it.
Tell me also how you run it, if it's by script, by direct execution, or through a startup script like ~/.bashrc.
top_level_dir ()
{
__DIR=$PWD
case "$__DIR" in
*home*)
echo home
;;
*scratch*)
echo scratch
;;
*project*)
echo project
;;
*)
echo "$__DIR"
;;
esac
}
export PS1='$(top_level_dir) : '
export -f top_level_dir
If it doesn't work, try changing __DIR=$PWD to __DIR=$(pwd) and tell us if it helps too. I also would like to confirm if you're really running bash. Note that there are many variants of sh like bash, zsh, ksh, and dash and the one installed and used by default depends on every system. To confirm that you're using Bash, do echo "$BASH_VERSION" and see if it shows a message.
You should also make sure that you're running export PS1='$(top_level_dir) : ' with single quotes and not with double quotes: export PS1="$(top_level_dir) : ".
Related
I have a global npm package that provided by a third party to generate a report and send it to server.
in_report generate -date 20221211
And I want to let a group of user to have the ability to check whether the report is generated or not, in order to prevent duplication. Therefore, I want to run a sh script before executing the in_report command.
sh check.sh && in_report generate -date 20221211
But the problem is I don't want to change the command how they generate the report. I can do a patch on their PC (able to change the env path or etc).
Is it possible to run sh check.sh && in_report generate -date 20221211 by running in_report generate -date 20221211?
If this "in_report" is only used for this exact purpose, you can create an alias by putting the following line at the end of the ".bashrc" or ".bash_aliases" file that is used by the people who will need to run in_report :
alias in_report='sh check.sh && in_report'
See https://doc.ubuntu-fr.org/alias for details.
If in_report is to be used in other ways too, this is not the solution. In that case, you may want to call it directly inside check.sh if a certain set of conditions on the parameters are matched. To do that :
alias in_report='sh check.sh'
The content of check.sh :
#!/bin/sh
if [[ $# -eq 3 && "$1" == "generate" && "$2" == "-date" && "$3" == "20"* ]] # Assuming that all you dates must be in the 21st century
then
if [[ some test to check that the report has not been generated yet ]]
then
/full/path/to/the/actual/in_report "$#" # WARNING : be sure that nobody will move the actual in_report to another path
else
echo "This report already exists"
fi
else
/full/path/to/the/actual/in_report "$#"
fi
This sure is not ideal but it should work. But by far the easiest and most reliable solution if applicable would be to ignore the aliasing thing and tell those who will use in_report to run your check.sh instead (with the same parameters as they would put to run in_report), and then you can directly call in_report instead of the /full/path/to/the/actual/in_report.
Sorry if this was not very clear. In that case, feel free to ask.
On most modern Linux distros the easiest would be to place a shell script that defines a function in /etc/profile.d, e.g. /etc/profile.d/my_report with a content of
function in_report() { sh check.sh && /path/to/in_report $*; }
That way it gets automatically placed in peoples environment when they log in.
The /path/to is important so the function doesn't call itself recursively.
A cursory glance through doco for the Mac suggests that you may want to edit /etc/bashrc or /etc/zshrc respectively.
I'm writing a script to troubleshoot problems that I encounter regularly.
One of the issues is /sbin missing from the path. But it's not always the case, so instead of indiscriminately adding it to .profile, .bash_profile, .bashrc, etc. like so:
echo "export PATH=\"$PATH:/sbin\"" >> ~/.bashrc
..and over time, ending up with multiple export PATHs with :/sbin:/sbin:/sbin:/sbin:/sbin on the end... well, you get the idea. How do I manage this?
Here's one way:
echo '[[ ":$PATH:" == *:/sbin:* ]] || PATH="$PATH:/sbin"' >> ~/.bashrc
(Note that you don't need the export, by the way, when updating what is already an environment variable.)
How it works:
For [[ expression ]] in general, and == in particular, see the Bash Reference Manual, § 3.2.4.2 "Conditional Constructs".
So [[ ":$PATH:" == *:/sbin:* ]] is a command that returns 0 (= success) if :$PATH: contains :/sbin:, and 1 (= non-success) otherwise.
For command1 || command2, see the Bash Reference Manual, § 3.2.3 "Lists of Commands".
So [[ ":$PATH:" == *:/sbin:* ]] || PATH="$PATH:/sbin" is a command-list that runs PATH="$PATH:/sbin" if :$PATH: contains :/sbin:, and otherwise not.
This may not be the "best" solution, but one I'm quite comfortable with. I've always liked using Python for my repetitive tasks that it would take too long to do properly in bash, and this definitely fits the bill.
The idea is to check if /sbin is present in $PATH, delimited by the start or end of the string, or a colon. grep or even extended test ([[) can do this for you pretty easily, but for a general solution, where the path of interest may have regex control characters, or you would have to escape parts of the string. It's much easier in Python than in bash: Is it possible to escape regex metacharacters reliably with sed. So I use a script like this (which actually avoids almost all manual parsing):
inpath
#/usr/bin/env python
"""
Checks if the sole argument is in the PATH.
Returns 0 if yes, 1 if no. It is an error to pass in more
than one command-line argument.
"""
import sys
from is import get_exec_path
from os path import abspath, normcase
if len(sys.argv) != 2:
raise ValueError('Exactly one command line argument must be provided')
path = [normcase(abspath(p)) for p in get_exec_path()]
sys.exit(sys.argv[1] not in path)
This can be implemented in any number of languages more simply than in bash; I just happen to be familiar with Python. It should work with any sane version, probably before even 2.6. It's written to run on Unix or Windows, although I'm going to guess that it's not really useful on the latter. Use it like this:
if inpath /sbin ; then
echo "export PATH=\"$PATH:/sbin\"" >> ~/.bashrc
fi
Or
inpath /sbin && echo "export PATH=\"$PATH:/sbin\"" >> ~/.bashrc
The pathmunge function is already defined in /etc/profile:
pathmunge () {
case ":${PATH}:" in
*:"$1":*)
;;
*)
if [ "$2" = "after" ] ; then
PATH=$PATH:$1
else
PATH=$1:$PATH
fi
esac
}
I'm new to linux and working in the terminal, and wrote a function to see if I'm on the company network or not
function isCompanyNetwork() {
if [[ $(ipconfig getifaddr en0) == 3.* ]] || [[ $(ipconfig getifaddr en1) == 3.* ]] ;
then
echo yes
else
echo no
fi
}
however, when i type the following in my terminal: isCompanyNetwork
I get:
-bash: isCompanyNetwork: command not found
what am I doing wrong?
Add this function to your ~/.bashrc
I'm guessing you wrote this in a file? If it's .bash_profile or .bashrc, you need to relog in or source the files (i.e. . ~/.bash_profile). If you did this at the command line and haven't logged out, you can see your defined fuctions by typing declare -F. Make sure isCompanyNetwork is there, or you did something wrong (created it in another window?).
I'm trying to set an environmental variable that will persist once the script has finished running. It can go away after I end an ssh session.
Sample bash script:
# User picks an option
1) export dogs = cool
2) export dogs = not_cool
Running the script as source script.sh doesn't work since it kicks me out of my shell when ran and also requires the interactive menu so it won't work. Basically I want the user to be able to pick an option to switch between environmental variables in their shell. Is that even possible?
Source:
#!/bin/bash
set -x
show_menu(){
NORMAL=`echo "\033[m"`
MENU=`echo "\033[36m"` #Blue
NUMBER=`echo "\033[33m"` #yellow
FGRED=`echo "\033[41m"`
RED_TEXT=`echo "\033[31m"`
ENTER_LINE=`echo "\033[33m"`
echo -e "${MENU}*********************************************${NORMAL}"
echo -e "${MENU}**${NUMBER} 1)${MENU} Option 1 ${NORMAL}"
echo -e "${MENU}**${NUMBER} 2)${MENU} Option 2 ${NORMAL}"
echo -e "${MENU}*********************************************${NORMAL}"
echo -e "${ENTER_LINE}Please enter a menu option and enter or ${RED_TEXT}enter to exit. ${NORMAL}"
read opt
}
function option_picked() {
COLOR='\033[01;31m' # bold red
RESET='\033[00;00m' # normal white
MESSAGE=${#:-"${RESET}Error: No message passed"}
echo -e "${COLOR}${MESSAGE}${RESET}"
}
clear
show_menu
while [ opt != '' ]
do
if [[ $opt = "" ]]; then
exit;
else
case $opt in
1) clear;
option_picked "Option 1";
export dogs=cool
show_menu;
;;
2) clear;
option_picked "Option 2";
export dogs=not_cool
show_menu;
;;
x)exit;
;;
\n)exit;
;;
*)clear;
option_picked "Pick an option from the menu";
show_menu;
;;
esac
fi
done
The problem here is that . ./script.sh or source ./script.sh cannot run an interactive menu style script like this one. No way that I'm aware of to set local environmental variables from a bash script like I am trying to do here.
Redirect your normal echo's for user interaction to stderr (>&2)
echo the value that you want to have in your parent's environment to stdout (>&1)
if you changed your script that way you can call it like:
ENV_VAR=$( /path/to/your_script arg1 arg2 arg3 arg_whatever )
and now you have "exported" a variable to the "parent"
Try running your script with "./myscript.sh" which will use the current shell without invoking the new shell (still i doubt the hash bang might invokes the new shell).
Have a look here
Can also be solved with ~/.bashrc. The required environments can added in this file. If you need new shell with your own environment, you invoke "bash" with "bash --rcfile ".
There are many questions asking about accessing the Sublime Text 2 editor from the command line. The responses, in summary, are to make a symlink, alias or simple shell script to run the appropriate sublime_text command. I can do that. What I want is to make the linux version behave like the MacOS version.
On MacOS, I have the following:
ln -s /Applications/Sublime\ Text\ 2.app/Contents/SharedSupport/bin/subl ~/bin/subl
Then in my .zshrc:
alias subl="$HOME/bin/subl -n"
export EDITOR="$HOME/bin/subl -n -w"
This does two things. It gives me a subl command that opens any files given on the command line in a new window. The subl command does not block the terminal. It also sets up my editor to open sublime text to edit the arguments, but this time it does block. In particular, $EDITOR blocks until its arguments are closed. It does not block on unrelated sublime text windows.
I can achieve a similar effect on linux with the following:
In ~/bin/subl:
#! /bin/zsh
$HOME/Sublime\ Text\ 2/sublime_text -n $# &
and then in ~/bin/subl_wait: (think mate_wait for TextMate users)
#! /bin/zsh
exec $HOME/Sublime\ Text\ 2/sublime_text -n -w $#
I can then set EDITOR to subl_wait, and things almost work. subl opens files for editing and doesn't block. subl_wait opens files for editing and does block.
The problem is that subl_wait is waiting until all open files are closed, not just its arguments.
Is it possible to get this working perfectly?
Looks like I've found the issue. (Thanks to this post: http://www.sublimetext.com/forum/viewtopic.php?f=2&t=7003 )
Basic point: sublime behaves differently depending upon whether an instance is already running!
If an instance is already running then sublime on linux behaves similarly to MacOS. If no instance is running then the terminal blocks until you exit sublime.
With that in mind, we just need to modify the scripts to make sure sublime is running:
in ~/bin/subl_start:
#! /bin/zsh
if [ ! "$(pidof sublime_text)" ] ; then
# start sublime text main instance
# echo "Starting Sublime Text 2"
$HOME/Sublime\ Text\ 2/sublime_text &
sleep 1 # needed to avoid a race condition
fi
in ~/bin/subl:
#! /bin/zsh
. $HOME/bin/subl_start
exec $HOME/Sublime\ Text\ 2/sublime_text -n $#
in ~/bin/subl_wait:
#! /bin/zsh
. $HOME/bin/subl_start
exec $HOME/Sublime\ Text\ 2/sublime_text -n -w $#
Note that I've used the -n flags everywhere. This might not be your cup of tea. If you are using -n then you possibly also want to look at your close_windows_when_empty setting.
Inspired by the OP's answer, I've created a bash wrapper script for Sublime Text that incorporates all your findings and runs on both OSX and Linux.
Its purpose is threefold:
provide a unified subl CLI that works like ST's own subl on OSX: invoke ST without blocking, unless waiting is explicitly requested.
encapsulate a workaround for the waiting-related bug on Linux.
when saved or symlinked to as sublwait, provide a sublwait CLI that automatically applies the --wait and --new-window options so as to make it suitable for use with $EDITOR (note that some programs, e.g. npm, require the $EDITOR to contain the name of an executable only - executables + options are not supported); also makes sure that at least one file is specified.
The only open question is whether the OP's approach to avoiding the race condition - sleep 1 - is robust enough.
Update:
Note that subl on OSX is by default NOT placed in the $PATH - you normally have to do that manually. If you haven't done so, the script will now locate subl inside ST's application bundle; (it tries app names in the following sequence: 'Sublime Text', 'Sublime Text 2', 'Sublime Text 3', first in /Applications, then in ~/Applications.)
Here's the output from running the script with -h:
Multi-platform (OSX, Linux) wrapper script for invocation of Sublime Text (ST)
from the command line.
Linux:
Works around undesired blocking of the shell (unless requested)
and a bug when waiting for specific files to be edited.
Both platforms:
When invoked as `sublwait`, automatically applies the
--wait --new-window
options to make it suitable for use with $EDITOR.
Therefore, you can to the following:
- Name this script `subl` for a CLI that supports ALL options.
(On OSX, this will simply defer to the `subl` CLI that came with ST.)
- Place the script in a directory in your $PATH.
- In the same directory, create a symlink to the `subl` script named
`sublwait`:
ln -s subl sublwait
and, if desired, add
export EDITOR=sublwait
to your shell profile.
Note that if you only use OSX, you can make do with ST's own subl and just save this script directly as sublwait.
Script source:
#!/usr/bin/env bash
# Multi-platform (OSX, Linux) wrapper script for invocation of Sublime Text (ST)
# from the command line. Invoke with -h for details.
[[ $1 == '-h' || $1 == '--help' ]] && showHelpOnly=1 || showHelpOnly=0
[[ $(basename "$BASH_SOURCE") == 'sublwait' ]] && invokedAsSublWait=1 || invokedAsSublWait=0
[[ $(uname) == 'Darwin' ]] && isOsX=1 || isOsX=0
# Find the platform-appropriate ST executable.
if (( isOsX )); then # OSX: ST comes with a bona-fide CLI, `subl`.
# First, try to find the `subl` CLI in the $PATH.
# Note: This CLI is NOT there by default; it must be created by symlinking it from
# its location inside the ST app bundle.
# Find the `subl` executable, ignoring this script, if named subl' as well, or a
# script by that name in the same folder as this one (when invoked via symlink 'sublwait').
stExe=$(which -a subl | fgrep -v -x "$(dirname "$BASH_SOURCE")/subl" | head -1)
# If not already in the path, look for it inside the application bundle. Try several locations and versions.
if [[ -z $stExe ]]; then
for p in {,$HOME}"/Applications/Sublime Text"{,' 2',' 3'}".app/Contents/SharedSupport/bin/subl"; do
[[ -f $p ]] && { stExe=$p; break; }
done
fi
[[ -x $stExe ]] || { echo "ERROR: Sublime Text CLI 'subl' not found." 1>&2; exit 1; }
else # Linux: `sublime_text` is the only executable - the app itself.
stExe='sublime_text'
which "$stExe" >/dev/null || { echo "ERROR: Sublime Text executable '$stExe' not found." 1>&2; exit 1; }
fi
# Show command-line help, if requested.
# Add preamble before printing ST's own help.
# Note that we needn't worry about blocking the
# shell in this case - ST just outputs synchronously
# to stdout, then exits.
if (( showHelpOnly )); then
bugDescr=$(
cat <<EOF
works around a bug on Linux (as of v2.0.2), where Sublime Text,
if it is not already running, mistakenly blocks until it is exited altogether.
EOF
)
if (( invokedAsSublWait )); then
# We provide variant-specific help here.
cat <<EOF
Wrapper script for Sublime Text suitable for use with the \$EDITOR variable.
Opens the specified files for editing in a new window and blocks the
invoking program (shell) until they are closed.
In other words: the --wait and --new-window options are automatically
applied.
Aside from encapsulating this functionality without the need for options
- helpful for tools that require \$EDITOR to be an executable name only -
$bugDescr
Usage: sublwait file ...
EOF
# Note: Adding other options doesn't make sense in this scenario
# (as of v2.0.2), so we do NOT show ST's own help here.
else
cat <<EOF
Multi-platform (OSX, Linux) wrapper script for invocation of
Sublime Text (ST) from the command line.
Linux:
Works around undesired blocking of the shell (unless requested)
and a bug when waiting for specific files to be edited.
Both platforms:
When invoked as \`sublwait\`, automatically applies the
--wait --new-window
options to make it suitable for use with \$EDITOR.
Therefore, you can to the following:
- Name this script \`subl\` for a CLI that supports ALL options.
(On OSX, this will simply defer to the \`subl\` CLI that came with ST.)
- Place the script in a directory in your \$PATH.
- In the same directory, create a symlink to the \`subl\` script named
\`sublwait\`:
ln -s subl sublwait
and, if desired, add
export EDITOR=sublwait
to your shell profile.
Sublime Text's own help:
------------------------
EOF
# Finally, print ST's own help and exit.
exec "$stExe" "$#"
fi
exit 0
fi
# Invoked as `sublwait`? -> automatically apply --wait --new-window options.
if (( invokedAsSublWait )); then
# Validate parameters.
# - We expect NO options - to keep things simple and predictable, we do NOT allow
# specifying additional options (beyond the implied ones).
# - We need at least 1 file argument.
# - As a courtesy, we ensure that no *directories* are among the arguments - ST doesn't support
# that properly (always waits for ST exit altogether); beyond that, however, we leave input
# validation to ST.
if [[ "$1" =~ ^-[[:alnum:]]+$ || "$1" =~ ^--[[:alnum:]]+[[:alnum:]-]+$ ]]; then # options specified?
{ echo "ERROR: Unexpected option specified: '$1'. Use -h for help." 1>&2; exit 1; }
elif (( $# == 0 )); then # no file arguments?
{ echo "ERROR: Missing file argument. Use -h for help." 1>&2; exit 1; }
else # any directories among the arguments?
# Note: We do NOT check for file existence - files could be created on demand.
# (Things can still go wrong - e.g., /nosuchdir/mynewfile - and ST doesn't
# handle that gracefully, but we don't want to do too much here.)
for f in "$#"; do
[[ ! -d "$f" ]] || { echo "ERROR: Specifying directories is not supported: '$f'. Use -h for help." 1>&2; exit 1; }
done
fi
# Prepend the implied options.
set -- '--wait' '--new-window' "$#"
fi
# Finally, invoke ST:
if (( isOsX )); then # OSX
# `subl` on OSX handles all cases correctly; simply pass parameters through.
exec "$stExe" "$#"
else # LINUX: `sublime_text`, the app executable itself, does have a CLI, but it blocks the shell.
# Determine if the wait option was specified.
mustWait=0
if (( invokedAsSublWait )); then
mustWait=1
else
# Look for the wait option in the parameters to pass through.
for p in "$#"; do
[[ $p != -* ]] && break # past options
[[ $p == '--wait' || $p =~ ^-[[:alnum:]]*w[[:alnum:]]*$ ]] && { mustWait=1; break; }
done
fi
if (( mustWait )); then # Invoke in wait-for-specified-files-to-close mode.
# Quirk on Linux:
# If sublime_text isn't running yet, we must start it explicitly first.
# Otherwise, --wait will wait for ST *as a whole* to be closed before returning,
# which is undesired.
# Thanks, http://stackoverflow.com/questions/14598261/making-sublime-text-2-command-on-linux-behave-as-it-does-on-macos-x
if ! pidof "$stExe" 1>/dev/null; then
# Launch as BACKGROUND task to avoid blocking.
# (Sadly, the `--background` option - designed not to activate the Sublime Text window
# on launching - doesn't actually work on Linux (as of ST v2.0.2 on Ubuntu 12.04).)
("$stExe" --background &)
# !! We MUST give ST some time to start up, otherwise the 2nd invocation below will be ignored.
# ?? Does a fixed sleep time of 1 second work reliably?
sleep 1
fi
# Invoke in blocking manner, as requested.
exec "$stExe" "$#"
else # Ensure invocation in NON-blocking manner.
if ! pidof "$stExe" 1>/dev/null; then # ST isn't running.
# If ST isn't running, invoking it *always* blocks.
# Therefore, we launch it as a background taks.
# Invocation via a subshell (parentheses) suppresses display of the
# background-task 'housekeeping' info.
("$stExe" "$#" &)
else # ST is already running, we can safely invoke it directly without fear of blocking.
exec "$stExe" "$#"
fi
fi
fi
On Ubuntu Gnu/Linux 13.04 64-bit:
I just keep subl running pretty much all the time. So my git config has:
core.editor=/usr/bin/subl -n -w
And that's all I need. I save the git commit file with ctrl-s, close the window with ctrl-w and I'm done. But I then have to really close the window by hitting the X in the upper corner... 96% perfect.