The mark " in Vim takes you to your last cursor position. I want to create an alias that will open my Vim instance and jump to that mark; something which is obviously extremely useful.
This works from the command line:
$ vim -c "'\"" File.cpp
Now I want to make an alias for this:
$ alias v='vim -c "'\""'
Well that's not going to work! You need to escape the first single quote you say...
$ alias v='vim -c "\'\""'
Hmm. That didn't work either... So I try a whole lot of variations of single quoted and double quoted madness, bang my head against the table and load up stackoverflow in my browser, and here we are.
How do I properly escape this alias?
Edit
In fact there is a better way to do this :h last-position-jump.
This autocommand jumps to the last known position in a file just after opening it, if the '" mark is set:
:au BufReadPost * if line("'\"") > 1 && line("'\"") <= line("$") | exe "normal! g'\"" | endif
Your question is an example of a situation in which functions are superior to aliases:
v() { vim -c "'\"" "$#"; }
This looks completely obscure, but should work:
alias v='vim -c "'"'"'\""'
That's a single-quoted vim -c ", followed by a double-quoted ', followed by a single-quoted \""...
Another solution is GNU Screen. It let's you save one or more shell instances (where one or more could be running vim) and saves their exact contents as if your computer would be idling. In particular, it's perfect for having many tabs and files open on a remote computer.
So instead of just going to the last mark, you'd simply type screen -r mysession and you'd restore not just the last position of the cursor, but all your buffers/tabs/shell instances/other programs and what not.
But perhaps you knew that already.
Related
Here's my .zshrc:
alias inst="adb install -r -d"
notify() {
start=$(date +%s)
"$#"
notify-send "\"$(echo $#)\" took $(($(date +%s) - start)) seconds to finish"
}
When I run the command notify inst app.apk, I get an error:
notify:2: command not found: inst
0.00s user 0.00s system 0% cpu 0.001 total
Can anyone shed some light on why this doesn't work, and hopefully a way to make it work?
When the shell processes commands, among other things (e.g. PATH search) it will check to see if the first token/argument (whitespace delimited) belongs to an alias loaded in the current environment. If the alias you are trying to substitute is not the first token, the substitution will not happen. If your alias happens to not be the name of an executable on the PATH or current directory, the error will propagate back up to a command not found.
Since your question is about the Z Shell, zsh actually provides a lesser-known feature called global aliasing. If an alias is declared with the -g flag, zsh will make the appropriate substitution for not only the first token, but any token, regardless of order.
alias -g inst="adb install -r -d" should do the trick.
Keep in mind that this is a zsh only feature for portability reasons, and make sure that whatever script your writing has a shebang line that invokes the zsh shell: #!/usr/bin/env zsh
I would also recommend to not use zsh global aliasing in important or production scripts. For personal use, it is perfectly fine.
Don't use alias for scripting
First, according to the advanced bash scripting guide:
In a script, aliases have very limited usefulness.
So you may consider not using alias but a function for instance (still from the same page, 2 paragraph lower):
Almost invariably, whatever we would like an alias to do could be accomplished much more effectively with a function.
A hacky solution
If this is for a quick script for yourself using aliases you have in your .zshrc, there is still a way out.
alias foo='echo hello'
bar() {
`alias "$#" | cut -d\' -f2`
}
bar foo # => hello
Alias replacement
from alias man page:
The first word of each simple command, if unquoted, is checked to see if it has an alias. If so, that word is replaced by the text of the alias. The alias name and the replacement text can contain any valid shell input, including shell metacharacters, with the exception that the alias name can not contain `='.
The first word of the replacement text is tested for aliases, but a word that is identical to an alias being expanded is not expanded a second time. This means that one can alias ls to "ls -F", for instance, and Bash does not try to recursively expand the replacement text.
Aliases are not expanded when the shell is not interactive, unless the expand_aliases shell option is set using shopt .
The rules concerning the definition and use of aliases are somewhat confusing. Bash always reads at least one complete line of input before executing any of the commands on that line. Aliases are expanded when a command is read, not when it is executed. Therefore, an alias definition appearing on the same line as another command does not take effect until the next line of input is read. The commands following the alias definition on that line are not affected by the new alias. This behavior is also an issue when functions are executed. Aliases are expanded when a function definition is read, not when the function is executed, because a function definition is itself a compound command. As a consequence, aliases defined in a function are not available until after that function is executed. To be safe, always put alias definitions on a separate line, and do not use alias in compound commands.
I have come across unix sed command usage and not able to understand what it does. Could you please help me to understand the usage ? If possible please share some reference to understand such usages of sed command.
sed -i '/^export JAVA_HOME/ s:.*:export JAVA_HOME=/usr/java/default\nexport HADOOP_PREFIX=/usr/local/hadoop\nexport HADOOP_HOME=/usr/local/hadoop\n:' $HADOOP_PREFIX/etc/hadoop/hadoop-env.sh
The command is simple, though it assumes GNU sed because of the way it uses the -i option; for macOS Sierra and related systems, you'd need to use -i '' in place of just -i.
Overall, it corresponds to:
sed -i '/Pattern/ s:.*:Replacement:' file
where:
-i means overwrite each input file with its edited output without creating a backup copy.
/Pattern/ is ^export JAVA_HOME; a line starting with the word export and then JAVA_HOME separated by a single space.
s:.*:Replacement: is a substitute command, using : instead of the more conventional / (often s/.*/Replacement/) as the pattern delimiter. This is done because the replacement text contains slashes. The .* matches the whole line. The rest of the material is written in place of the original export JAVA_HOME line. The \n sequence expands to a newline, so it actually produces a number of lines in the output.
file is $HADOOP_PREFIX/etc/hadoop/hadoop-env.sh
As others have pointed out, this is a sed command invocation. The command is short for "Stream EDitor" and is quite useful for modifying files programaticallly. Your best bet is to read the man pages (man sed, but I've broken down your particular command here for instructive purposes:
sed # The command
-i # Edit file in place (no backup)
'/^export JAVA_HOME/ # For every line that begins with 'export JAVA_HOME'...
s: # substitue...
.*: # the entire line with...
export JAVA_HOME=/usr/java/default
export HADOOP_PREFIX=/usr/local/hadoop
export HADOOP_HOME=/usr/local/hadoop
:' # End of command
$HADOOP_PREFIX/etc/hadoop/hadoop-env.sh # Run on the following file
Points of interest:
Commands can be limited to a particular address range or scope. Here, the scope was a search.
The substitue command can be delimited by almost any character (usually it is /, but in this case, : was chosen to prevent escaping of the / in the filepaths
The sed expression was enclosed in ' to prevent shell expansion of variables. Although no expansions would have taken place in this scenario, it is fairly common to see the expression wrapped in ' to eliminate the possibility.
Really quirky title, I know.
Basically, I have this:
alias vv="xclip -selection clipboard -o"
which prints out anything in my clipboard, such as a repository location in ssh-form (git#github.username/repname.git).
Now I'd like to:
git clone vv
I tried several variations of the above, such as trying various switches on the alias, or using different expansions, but with no luck.
Any suggestions?
Global alias might do it... actually it does it:
alias -g vv="$(date)" # replace 'date' with your command of choice
Notice:
it is a global alias, so it works anywhere in the command line (not just the beginning)
$(...) will do command substitution and expand it as a variable, see man zshexpn and search for $(...). By default zsh will not break the results using white-spaces.
[...]
I initially wrote a suggestion to create a (zsh) widget to insert the clipboard into the command line with a given key combination, then I realized that you would just likely hit "Ctrl-Shift-V" or something... :-S
[...]
FYI, this is how you would do this using a zsh widget:
that inserts the clipboard content on the command line, and binding it to some key, as it would allow you to see what you are doing before hitting enter. Place the following into your $fpath, inside a file called insert-clipboard (needs to be loaded with KSH_AUTOLOAD set)
#! /bin/zsh
## Inserts the output of the command into the cmd line buffer
zmodload -i zsh/parameter
insert-clipboard() {
LBUFFER+="$(date)" # REPLACE date BY YOUR COMMAND!
}
At your .zshrc
autoload insert-clipboard # as written, it needs KSH_AUTOLOAD set....
zle -N insert-clipboard
bindkey '^Xu' insert-clipboard # pick a key combination you like...
When I search in, for example, man ls while in a tmux session, the search strings don't appear highlighted - the page jumps down so that the search string is on the top line of the buffer, as expected, but it's not highlighted.
Doing the same thing in the same shell while not in a tmux session results in highlighted search strings.
I have no idea where to start looking to solve this. Any hints are appreciated.
Based on Less Colors For Man Pages by Gen2ly, here is my man page and how to do it:
Preview
This is a shell, not a web page !
How to
(optional) I'm using Tomorrow theme for Konsole/Yakuake ;
Edit your ~/.bashrc ~/.zshrc, etc. to add :
# Colored man pages: http://linuxtidbits.wordpress.com/2009/03/23/less-colors-for-man-pages/
# Less Colors for Man Pages
export LESS_TERMCAP_mb=$'\E[01;31m' # begin blinking
export LESS_TERMCAP_md=$'\E[01;38;5;74m' # begin bold
export LESS_TERMCAP_me=$'\E[0m' # end mode
export LESS_TERMCAP_se=$'\E[0m' # end standout-mode
export LESS_TERMCAP_so=$'\E[38;5;016m\E[48;5;220m' # begin standout-mode - info box
export LESS_TERMCAP_ue=$'\E[0m' # end underline
export LESS_TERMCAP_us=$'\E[04;38;5;146m' # begin underline
Reload your config and try a man page search :
. ~/.bashrc && man ls
Fixed it. The problem is to do with the way that the screen $TERM handles italics. From the tmux FAQ:
vim displays reverse video instead of italics, while less displays italics
(or just regular text) instead of reverse. What's wrong?
This matches my problem exactly. The $PAGER used by man is less by default - basically, man uses less to show the contents of the manual pages. In my case, less wasn't highlighting text, just showing regular text.
The reason for this happening:
Screen's terminfo description lacks italics mode and has standout mode in its
place, but using the same escape sequence that urxvt uses for italics. This
means applications (like vim) looking for italics will not find it and might
turn to reverse in its place, while applications (like less) asking for
standout will end up with italics instead of reverse.
The solution is to make a new terminfo file for tmux, which lets it know that italics are supported. The solution's outlined in the (at time of writing) very, very bottom of the tmux FAQ.
After creating the new terminfo file, in tmux: C-b :source-file /absolute/path/to/.tmux.conf (from this SuperUser question) - this should make tmux reload the .tmux.conf file. However, this didn't work for me, and the changes only applied after restarting the tmux server (close all tmux sessions, then re-open them).
This thread is a few years old but is still the one that comes up as the best search result, so I'm answering with what finally worked for me. This is based off of tmux FAQ.
...but the instructions aren't completely clear on when or where to substitute the -256color string. I use gnome-terminal (v 3.16.2) with tmux, and this worked for me:
$ mkdir $HOME/.terminfo/
$ screen_terminfo="screen-256color"
$ infocmp "$screen_terminfo" | sed \
-e 's/^screen[^|]*|[^,]*,/screen-256color|screen with italics support,/' \
-e 's/%?%p1%t;3%/%?%p1%t;7%/' \
-e 's/smso=[^,]*,/smso=\\E[7m,/' \
-e 's/rmso=[^,]*,/rmso=\\E[27m,/' \
-e '$s/$/ sitm=\\E[3m, ritm=\\E[23m,/' > /tmp/screen.terminfo
$ tic /tmp/screen.terminfo
And tell tmux to use it in ~/.tmux.conf:
set -g default-terminal "screen-256color"
Note: I tried it once without the -256color and since that didn't work (still seeing italics instead of highlighting), I had to delete everything under the .terminfo dir (another dir called 's') before the infocmp would work.
I like keeping my history files uncluttered. Since zsh has excellent history searching features, there is no need to save all the commands that I repeatedly use (e.g., finger, pwd, ls, etc) multiple times. To strip the history file of all duplicate lines, I did sort .zhistory|uniq -du. Now, I'd like to write this back to the same file, so that if I simply put this in my .zshrc, everytime I login, my history is trimmed and clean. If I try sort .zhistory|uniq -du>.zhistory, the resulting file is empty! On the other hand, if I do sort .zhistory|uniq -du>tempfile, it writes to tempfile correctly. Any idea how I can write to the same file?
You might be able to use a variable:
file='.zhistory' && var=$(sort -u "$file") && echo "$var" > "$file"
The reason you can't write to the same file is that the redirection occurs first and truncates the file before the utility ever sees it.
You can prevent duplicate lines in the first place. Use setopt with one or more of the following settings (from man zshoptions):
HIST_EXPIRE_DUPS_FIRST
If the internal history needs to be trimmed to add the current
command line, setting this option will cause the oldest history
event that has a duplicate to be lost before losing a unique
event from the list. You should be sure to set the value of
HISTSIZE to a larger number than SAVEHIST in order to give you
some room for the duplicated events, otherwise this option will
behave just like HIST_IGNORE_ALL_DUPS once the history fills up
with unique events.
HIST_FIND_NO_DUPS
When searching for history entries in the line editor, do not
display duplicates of a line previously found, even if the
duplicates are not contiguous.
HIST_IGNORE_ALL_DUPS
If a new command line being added to the history list duplicates
an older one, the older command is removed from the list (even
if it is not the previous event).
HIST_IGNORE_DUPS (-h)
Do not enter command lines into the history list if they are
duplicates of the previous event.
HIST_SAVE_NO_DUPS
When writing out the history file, older commands that duplicate
newer ones are omitted.
The program sponge can be useful to write back in the same file you read.
(For the example's sake, you don't know about sed -i)
echo "say what again" > file
sed s/what/woot/ file > file
So bad, file is now empty, you lost your file.
echo "say what again" > file
sed s/what/woot/ file | sponge file
does what you want
(Be careful not to write sponge > file or the file will be empty again.)
The fact that i didn't have an answer to this question annoyed me sufficiently that i wrote one - call this inplace and put it executably on your path:
#! /bin/bash
BACKUP_EXT=
while getopts "b:" flag
do
case "$flag" in
b) BACKUP_EXT="$OPTARG" ;;
esac
done
shift $((OPTIND - 1))
CMD="$1"
shift
for filename in "$#"
do
TMP_FILE="$(mktemp -t)"
bash -c "$CMD" <"$filename" >"$TMP_FILE"
if [[ -n "$BACKUP_EXT" ]]
then
mv "$filename" "$filename.$BACKUP_EXT"
fi
mv "$TMP_FILE" "$filename"
done
You may now say:
inplace 'sort | uniq -du' .zhistory
Incidentally, there's a way to do that uniqification without having to sort - but that's an answer for another question!