I found a nice zsh command online that uses fzf to fuzzy-search shell history:
fh() {
eval $( ([ -n "$ZSH_NAME" ] && fc -l 1 || history) | fzf +s --tac | sed 's/ *[0-9]* *//')
}
However, instead of eval-ing the command, I'd like to place it in my prompt and edit it further before running it, something like:
$ fh grep
(search happens)
$ grep -RI foo . <--- cursor
I tried replacing eval with echo, which is better but doesn't give me the command to edit. Is there a way to do this in bash/zsh?
Here is a related thread with a suggestion to use xvkbd, but I was hoping there is something simpler.
In zsh, the vared builtin for the zsh line editor (ZLE) will let you edit an environment variable.
After editing, the updated variable can be used to execute the command:
fh() {
fzfresult=$( ([ -n "$ZSH_NAME" ] && fc -l 1 || history) | fzf +s --tac | sed 's/ *[0-9]* *//')
vared -p 'fzfout> ' -ac fzfresult
${fzfresult[#]}
}
In the vared command, -p sets the prompt. The -ac option changes the fzfresult variable to an array so we can execute it in the next step.
I don't have fzf installed, so this isn't completely tested, but the result should look like this:
% fh grep
fzfout> grep -RI foo . <-- edit, hit enter, get output:
file1: text with foo
file4: more text with foobar
I ended up using this:
fh() {
print -s $( ([ -n "$ZSH_NAME" ] && fc -l 1 || history) | fzf +s --tac | sed 's/ *[0-9]* *//')
}
ie silently print, followed by up-arrow, which brings up the command for editing. Would love to hear if there is a simpler way.
Related
Trying to run a command as a variable but I am getting strange results
Expected result "1" :
grep -i nosuid /etc/fstab | grep -iq nfs
echo $?
1
Unexpected result as a variable command:
cmd="grep -i nosuid /etc/fstab | grep -iq nfs"
$cmd
echo $?
0
It seems it returns 0 as the command was correct not actual outcome. How to do this better ?
You can only execute exactly one command stored in a variable. The pipe is passed as an argument to the first grep.
Example
$ printArgs() { printf %s\\n "$#"; }
# Two commands. The 1st command has parameters "a" and "b".
# The 2nd command prints stdin from the first command.
$ printArgs a b | cat
a
b
$ cmd='printArgs a b | cat'
# Only one command with parameters "a", "b", "|", and "cat".
$ $cmd
a
b
|
cat
How to do this better?
Don't execute the command using variables.
Use a function.
$ cmd() { grep -i nosuid /etc/fstab | grep -iq nfs; }
$ cmd
$ echo $?
1
Solution to the actual problem
I see three options to your actual problem:
Use a DEBUG trap and the BASH_COMMAND variable inside the trap.
Enable bash's history feature for your script and use the hist command.
Use a function which takes a command string and executes it using eval.
Regarding your comment on the last approach: You only need one function. Something like
execAndLog() {
description="$1"
shift
if eval "$*"; then
info="PASSED: $description: $*"
passed+=("${FUNCNAME[1]}")
else
info="FAILED: $description: $*"
failed+=("${FUNCNAME[1]}")
done
}
You can use this function as follows
execAndLog 'Scanned system' 'grep -i nfs /etc/fstab | grep -iq noexec'
The first argument is the description for the log, the remaining arguments are the command to be executed.
using bash -x or set -x will allow you to see what bash executes:
> cmd="grep -i nosuid /etc/fstab | grep -iq nfs"
> set -x
> $cmd
+ grep -i nosuid /etc/fstab '|' grep -iq nfs
as you can see your pipe | is passed as an argument to the first grep command.
I want to transform a string given in this form:
xyx some commands
into this form:
alias xyz="some commands"
I tried different combinations in the terminal. It seems (i'm not sure) that it worked once, but never when i run this from the script. I've read somewhere that this is a variable problem.
Alias for readability:
alias first="sed 's/\s.*//'"
alias rest="sed 's/\S*\s*//'"
cat f_in | tee -a >(one=$(first)) >(two=$(rest)) | tee >(awk '{print "alias "$1"=\""$2"\""}' > f_out )
I used awk in this way to parse "cat f_in" into "print". It doesn't work. Then, i used "awk -v" but it still doesn't work too. How to redirect variable $one and $two into awk:
{one=$(first) === first | read -r one }?
Is this what you're trying to do:
$ echo 'xyx some commands' |
awk '{var=$1; sub(/^[^[:space:]]+[[:space:]]+/,""); printf "alias %s=\"%s\"\n", var, $0}'
alias xyx="some commands"
$ echo 'xyx some commands' |
sed 's/\([^[:space:]]*\)[[:space:]]*\(.*\)/alias \1="\2"/'
alias xyx="some commands"
I am wondering why I do not get se same output from:
ls -1 -tF | head -n 1
and
echo $(ls -1 -tF | head -n 1)
I tried to get the last modified file, but using it inside a sub shell sometimes I get more than one file as result?
Why that and how to avoid?
The problem arises because you are using an unquoted subshell and -F flag for ls outputs shell special characters appended to filenames.
-F, --classify
append indicator (one of */=>#|) to entries
Executable files are appended with *.
When you run
echo $(ls -1 -tF | head -n 1)
then
$(ls -1 -tF | head -n 1)
will return a filename, and if it happens to be an executable and also be the prefix to another file, then it will return both.
For example if you have
test.sh
test.sh.backup
then it will return
test.sh*
which when echoed expands to
test.sh test.sh.backup
Quoting the subshell prevents this expansion
echo "$(ls -1 -tF | head -n 1)"
returns
test.sh*
I just found the error:
If you use echo $(ls -1 -tF | head -n 1)
the file globing mechanism may result in additional matches.
So echo "$(ls -1 -tF | head -n 1)" would avoid this.
Because if the result is an executable it contains a * at the end.
I tried to place the why -F in a comment, but now I decided to put it here:
I added the following lines to my .bashrc, to have a shortcut to get last modified files or directories listed:
function L {
myvar=$1; h=${myvar:="1"};
echo "last ${h} modified file(s):";
export L=$(ls -1 -tF|fgrep -v / |head -n ${h}| sed 's/\(\*\|=\|#\)$//g' );
ls -l $L;
}
function LD {
myvar=$1;
h=${myvar:="1"};
echo "last ${h} modified directories:";
export LD=$(ls -1 -tF|fgrep / |head -n $h | sed 's/\(\*\|=\|#\)$//g'); ls -ld $LD;
}
alias ol='L; xdg-open $L'
alias cdl='LD; cd $LD'
So now I can use L (or L 5) to list the last (last 5) modified files. But not directories.
And with L; jmacs $L I can open my editor, to edit it. Traditionally I used my alias lt='ls -lrt' but than I have to retype the name...
Now after mkdir ... I use cdl to change to that dir.
I'm trying to create a ZSH auto completion script for Symfony's Console, I almost finished it but I block in the last part. I need to create an array thanks to a function returns, but I don't know how to process.
Here's the code I wrote:
_find_console () {
echo "php $(find . -maxdepth 2 -mindepth 1 -name 'console' -type f | head -n 1)"
}
_console_get_command_list () {
`_find_console` --no-ansi | \
sed "1,/Available commands/d" | \
awk '/ [a-z]+/ { print $0 }' | \
sed -E 's/^[ ]+//g' | \
sed -E 's/[:]+/\\:/g' | \
sed -E 's/[ ]{2,}/\:/g'
}
_console () {
local -a commands
commands=(`_console_get_command_list`)
_describe 'commands' commands
}
compdef _console php console
compdef _console console
If I execute the command line, it formats it in the proper way. But used with ZSH the output is like this:
acme:hello -- Hello
assets:install -- Installs
cache:warmup -- Warms
and the formatted function returns:
acme\:hello:Hello World example command
assetic\:dump:Dumps all assets to the filesystem
cache\:warmup:Warms up an empty cache
The words that are not displayed, are used as a command completion. Here's an example: Asciinema example.
If I take the returns and use it directly into the array, it works well.
Is it possible to add spaces to the left of every output to stdout (and stderr if possible) when I run commands in a bash shell script?
I'd like to do something like:
#!/bin/bash
echo Installing: Something
echo " => installing prerequisite1"
## INSERT MAGICAL LEFT SPACES COMMAND HERE ##
apt-get install -q -y prerequisite
## ANOTHER MAGICAL CANCELLING LEFT SPACES COMMAND HERE ##
echo " => installing prerequisite2"
# ... the padding again ...
wget http://abc.com/lostzilla.tar.gz
tar vzxf lostzilla.tar.gz
cd lostzilla-1.01
./configure
make && make install
# ... end of padding ...
echo Done.
Any idea?
EDIT: Added quotes to the echo command, otherwise they won't be padded.
Yes, you can quote them for simple things:
echo ' => installing prerequisite1'
and pipe the output through sed for complex things:
tar vzxf lostzilla.tar.gz 2>&1 | sed 's/^/ /'
The 2>&1 puts stdout and stderr onto the stdout stream and the sed replaces every start-of-line marker with three spaces.
How well this will work on something like wget which does all sorts of cursor manipulations I'm not sure.
Example shown here:
pax> ls -1 p*
phase1.py
phase1.sh
phase2.py
phase2.sh
primes.c
primes.exe
primes.sh
primes.stat
pax> ls -1 p* | sed 's/^/ /'
phase1.py
phase1.sh
phase2.py
phase2.sh
primes.c
primes.exe
primes.sh
primes.stat
One trick I've used in the past is to ensure that the scripts themselves take care of the indentation:
#!/bin/bash
if [[ "${DONT_EVER_SET_THIS_VAR}" = "" ]] ; then
export DONT_EVER_SET_THIS_VAR=except_for_here
$0 | sed 's/^/ /'
exit
fi
ls -1 p*
This will re-run the script with indentation through sed if it's not already doing so. That way, you don't have to worry about changing all your output statements. A bit of a hack, I know, but I tend to just do what's necessary for quick-and-dirty shell scripts.
If you want to turn spacing on and off, use the following awk script:
#!/usr/bin/gawk -f
/^#SPACEON/ { spaces=1; }
/^#SPACEOFF/ { spaces=0; }
!/^#SPACE/ {
if(spaces) {
print " " $0;
} else {
print $0;
}
}
Note that there are slight problems with your bash scipt. Notably, the use of => in your echo statements will output the character = to the file "installing".
#!/bin/bash
echo Installing: Something
echo '=> installing prerequisite1'
echo '#SPACEON'
echo You would see apt-get install -q -y prerequisite
echo '#SPACEOFF'
echo '=> installing prerequisite2'
echo '#SPACEON'
echo You would see wget http://abc.com/lostzilla.tar.gz
echo You would see tar vzxf lostzilla.tar.gz
echo You would see cd lostzilla-1.01
echo You would see ./configure
echo You would see make \&\& make install
echo '#SPACEOFF'
echo Done.
Combining the two gives me:
$ ./do-stuff | ./magic-spacing
Installing: Something
=> installing prerequisite1
You would see apt-get install -q -y prerequisite
=> installing prerequisite2
You would see wget http://abc.com/lostzilla.tar.gz
You would see tar vzxf lostzilla.tar.gz
You would see cd lostzilla-1.01
You would see ./configure
You would see make && make install
Done.
Where do-stuff is your bash script and magic-spacing is my awk script above.
Depending on how the command writes to stdout, you can just indent with a simple awk script:
$ echo -e 'hello\nworld' | awk '{print " ",$0}'
hello
world
Quite un-magical you can use printf to do the following:
# space padding for single string
printf "%-4s%s\n" "" "=> installing prerequisite1"
# space padding for single command output
# use of subshell leaves original IFS intact
( IFS=$'\n'; printf " %s\n" $(command ls -ld * 2>&1) )
# note: output to stderr is unbuffered
( IFS=$'\n'; printf " %s\n" $(command ls -ld * 1>&2) )
It's also possible to group commands by enclosing them in curly braces and space-padd their output like so:
{
cmd1 1>&2
cmd2 1>&2
cmd3 1>&2
} 2>&1 | sed 's/.*/ &/'
It's possible to redirect stdout to stderr script/shell-wide using exec ...
(
exec 1>&2
command ls -ld *
) 2>&1 | sed 's/^/ /'
Use python pyp (The Pyed Piper):
ls -ld | pyp "' '+p"