I would like to get file (zip file) from path with this part of code file=$(cd '/path_to_zip_file' | ls -t | head -1). Instead that I got my .sh file in directory where I am running this file.
Why I can't file from /path_to_zip_file
Below is my code in .sh file
file=$(cd '/path_to_zip_file' | ls -t | head -1)
last_modified=`stat -c "%Y" $file`;
current=`date +%s`
echo $file
if [ $(($current-$last_modified)) -gt 86400 ]; then
echo 'Mail'
else
echo 'No Mail'
fi;
If you were going to use ls -t | head -1 (which you shouldn't), the cd would need to be corrected as a prior command (happening before ls takes place), not a pipeline component (running parallel with ls, with its stdout connected to ls's stdin):
set -o pipefail # otherwise, a failure of ls is ignored so long as head succeeds
file=$(cd '/path_to_zip_file' && ls -t | head -1)
A better-practice approach might look like:
newest_file() {
local result=$1; shift # first, treat our first arg as latest
while (( $# )); do # as long as we have more args...
[[ $1 -nt $result ]] && result=$1 # replace "result" if they're newer
shift # then take them off the argument list
done
[[ -e $result || -L $result ]] || return 1 # fail if no file found
printf '%s\n' "$result" # more reliable than echo
}
newest=$(newest_file /path/to/zip/file/*)
newest=${newest##*/} ## trim the path to get only the filename
printf 'Newest file is: %s\n' "$newest"
To understand the ${newest##*/} syntax, see the bash-hackers' wiki on parameter expansion.
For more on why using ls in scripts (except for output displayed to humans) is dangerous, see ParsingLs.
Bot BashFAQ #99, How do I get the latest (or oldest) file from a directory? -- and BashFAQ #3 (How can I sort or compare files based on some metadata attribute (newest / oldest modification time, size, etc)?) have useful discussion on the larger context in which this question was asked.
Related
I have made two programms and I'm trying to call the one from the other but this is appearing on my screen:
cp: cannot stat ‘PerShip/.csv’: No such file or directory
cp: target ‘tmpship.csv’ is not a directory
I don't know what to do. Here are the programms. Could somebody help me please?
#!/bin/bash
shipname=$1
imo=$(grep "$shipname" shipsNAME-IMO.txt | cut -d "," -f 2)
cp PerShip/$imo'.csv' tmpship.csv
dist=$(octave -q ShipDistance.m 2>/dev/null)
grep "$shipname" shipsNAME-IMO.txt | cut -d "," -f 2 > IMO.txt
idnumber=$(cut -b 4-10 IMO.txt)
echo $idnumber,$dist
#!/bin/bash
rm -f shipsdist.csv
for ship in $(cat shipsNAME-IMO.txt | cut -d "," -f 1)
do
./FindShipDistance "$ship" >> shipsdist.csv
done
cat shipsdist.csv | sort | head -n 1
The code and error messages presented suggest that the second script is calling the first with an empty command-line argument. That would certainly happen if input file shipsNAME-IMO.txt contained any empty lines or otherwise any lines with an empty first field. An empty line at the beginning or end would do it.
I suggest
using the read command to read the data, and manipulating IFS to parse out comma-delimited fields
validating your inputs and other data early and often
making your scripts behave more pleasantly in the event of predictable failures
More generally, using internal Bash features instead of external programs where the former are reasonably natural.
For example:
#!/bin/bash
# Validate one command-line argument
[[ -n "$1" ]] || { echo empty ship name 1>&2; exit 1; }
# Read and validate an IMO corresponding to the argument
IFS=, read -r dummy imo tail < <(grep -F -- "$1" shipsNAME-IMO.txt)
[[ -f PerShip/"${imo}.csv" ]] || { echo no data for "'$imo'" 1>&2; exit 1; }
# Perform the distance calculation and output the result
cp PerShip/"${imo}.csv" tmpship.csv
dist=$(octave -q ShipDistance.m 2>/dev/null) ||
{ echo "failed to compute ship distance for '${imo}'" 2>&1; exit 1; }
echo "${imo:3:7},${dist}"
and
#!/bin/bash
# Note: the original shipsdist.csv will be clobbered
while IFS=, read -r ship tail; do
# Ignore any empty ship name, however it might arise
[[ -n "$ship" ]] && ./FindShipDistance "$ship"
done < shipsNAME-IMO.txt |
tee shipsdist.csv |
sort |
head -n 1
Note that making the while loop in the second script part of a pipeline will cause it to run in a subshell. That is sometimes a gotcha, but it won't cause any problem in this case.
I'm still new to the shell and need some help.
I have a file stapel_old.
Also I have in the same directory files like english_old_sync, math_old_sync and vocabulary_old_sync.
The content of stapel_old is:
english
math
vocabulary
The content of e.g. english is:
basic_grammar.md
spelling.md
orthography.md
I want to manipulate all files which are given in stapel_old like in this example:
take the first line of stapel_old 'english', (after that math, and so on)
convert in this case english to english_old_sync, (or after that what is given in second line, e.g. math to math_old_sync)
search in english_old_sync line by line for the pattern '.md'
And append to each line after .md :::#a1
The result should be e.g. of english_old_sync:
basic_grammar.md:::#a1
spelling.md:::#a1
orthography.md:::#a1
of math_old_sync:
geometry.md:::#a1
fractions.md:::#a1
and so on. stapel_old should stay unchanged.
How can I realize that?
I tried with sed -n, while loop (while read -r line), and I'm feeling it's somehow the right way - but I still get errors and not the expected result after 4 hours inspecting and reading.
Thank you!
EDIT
Here is the working code (The files are stored in folder 'olddata'):
clear
echo -e "$(tput setaf 1)$(tput setab 7)Learning directories:$(tput sgr 0)\n"
# put here directories which should not become flashcards, command: | grep -v 'name_of_directory_which_not_to_learn1' | grep -v 'directory2'
ls ../ | grep -v 00_gliederungsverweise | grep -v 0_weiter | grep -v bibliothek | grep -v notizen | grep -v Obsidian | grep -v z_nicht_uni | tee olddata/stapel_old
# count folders
echo -ne "\nHow much different folders: " && wc -l olddata/stapel_old | cut -d' ' -f1 | tee -a olddata/stapel_old
echo -e "Are this learning directories correct? [j ODER y]--> yes; [Other]-->no\n"
read lernvz_korrekt
if [ "$lernvz_korrekt" = j ] || [ "$lernvz_korrekt" = y ];
then
read -n 1 -s -r -p "Learning directories correct. Press any key to continue..."
else
read -n 1 -s -r -p "Learning directories not correct, please change in line 4. Press any key to continue..."
exit
fi
echo -e "\n_____________________________\n$(tput setaf 6)$(tput setab 5)Found cards:$(tput sgr 0)$(tput setaf 6)\n"
#GET && WRITE FOLDER NAMES into olddata/stapel_old
anzahl_zeilen=$(cat olddata/stapel_old |& tail -1)
#GET NAMES of .md files of every stapel and write All to 'stapelname'_old_sync
i=0
name="var_$i"
for (( num=1; num <= $anzahl_zeilen; num++ ))
do
i="$((i + 1))"
name="var_$i"
name=$(cat olddata/stapel_old | sed -n "$num"p)
find ../$name/ -name '*.md' | grep -v trash | grep -v Obsidian | rev | cut -d'/' -f1 | rev | tee olddata/$name"_old_sync"
done
(tput sgr 0)
I tried to add:
input="olddata/stapel_old"
while IFS= read -r line
do
sed -n "$line"p olddata/stapel_old
done < "$input"
The code to change only the english_old_sync is:
lines=$(wc -l olddata/english_old_sync | cut -d' ' -f1)
for ((num=1; num <= $lines; num++))
do
content=$(sed -n "$num"p olddata/english_old_sync)
sed -i "s/"$content"/""$content":::#a1/g"" olddata/english_old_sync
done
So now, this need to be a inner for-loop, of a outer for-loop which holds the variable for english, right?
stapel_old should stay unchanged.
You could try a while + read loop and embed sed inside the loop.
#!/usr/bin/env bash
while IFS= read -r files; do
echo cp -v "$files" "${files}_old_sync" &&
echo sed '/^.*\.md$/s/$/:::#a1/' "${files}_old_sync"
done < olddata/staple_old
convert in this case english to english_old_sync, (or after that what is given in second line, e.g. math to math_old_sync)
cp copies the file with a new name, if the goal is renaming the original file name from the content of the file staple_old then change cp to mv
The -n and -i flag from sed was ommited , include it, if needed.
The script also assumes that there are no empty/blank lines in the content of staple_old file. If in case there are/is add an addition test after the line where the do is.
[[ -n $files ]] || continue
It also assumes that the content of staple_old are existing files. Just in case add an additional test.
[[ -e $files ]] || { printf >&2 '%s no such file or directory.\n' "$files"; continue; }
Or an if statement.
if [[ ! -e $files ]]; then
printf >&2 '%s no such file or directory\n' "$files"
continue
fi
See also help test
See also help continue
Combining them all together should be something like:
#!/usr/bin/env bash
while IFS= read -r files; do
[[ -n $files ]] || continue
[[ -e $files ]] || {
printf >&2 '%s no such file or directory.\n' "$files"
continue
}
echo cp -v "$files" "${files}_old_sync" &&
echo sed '/^.*\.md$/s/$/:::#a1/' "${files}_old_sync"
done < olddata/staple_old
Remove the echo's If you're satisfied with the output so the script could copy/rename and edit the files.
for d in */ ; do
cd $d
NUM = $(echo ${PWD##*/} | grep -q "*abc*");
if [[ "$NUM" -ne "0" ]]; then
pwd
fi
cd ..
done
Here I'm trying to match a folder name to some substring 'abc' in the name of the folder and check if the output of the grep is not 0. But it gives me an error which reads that NUM: command not found
An error was addressed in comments.
NUM = $(echo ${PWD##*/} | grep -q "*abc*"); should be NUM=$(echo ${PWD##*/} | grep -q "*abc*");.
To clarify, the core problem would be to be able to match current directory name to a pattern.
You can probably simply the code to just
if grep -q "*abc*" <<< "${PWD##*/}" 2>/dev/null; then
echo "$PWD"
# Your rest of the code goes here
fi
You can use the exit code of the grep directly in a if-conditional without using a temporary variable here ($NUM here). The condition will pass if grep was able to find a match. The here-string <<<, will pass the input to grep similar to echo with a pipeline. The part 2>/dev/null is to just suppress any errors (stderr - file descriptor 2) if grep throws!
As an additional requirement asked by OP, to negate the conditional check just do
if ! grep -q "*abc*" <<< "${PWD##*/}" 2>/dev/null; then
There's the following part in a shell script I'm writing:
(Find the latest directory in someDir which is not summary/)
latestDirName=""
for dirName in `ls -lt /user/someDir/ | head -3 | tail -n +2 | awk '{print $9}'`
do
if [ "$dirName" == "summary" ]; then
continue
fi
latestDirName=$dirName
done
Here $dirname is compared against string summary, while an echo of dirName variable during the iteration will print as summary/
This comparison part works all fine when the code is written in a file and executed.
But once this same code is put inside a function and placed in my bashrc, the comparison in if check doesn't seem to work!
Does this have anything to do with the string being a directory name, or it having the /?
What difference does it make when the same code is inside a function?
Code inside bashrc:
findLatestDir()
{
latestDirName=""
for dirName in `ls -lt /user/someDir/ | head -3 | tail -n +2 | awk '{print $9}'`
do
if [ "$dirName" == "summary" ]; then
continue
fi
latestDirName=$dirName
done
}
The scripts are called as follows:
Case #1 (code in file): $ ./findLatestDir.sh
Case #2 (function in bashrc): $ findLatestDir
Maybe you have an alias or function definition for ls in your .bashrc, which interacts poorly with your use of ls in the function? If so, explicitly saying /bin/ls in the function may solve the problem.
Parsing ls is never a good idea. Use stat instead: print out the epoch modification time, sort numerically in descending order, then find the first dir that is not "summary".
findLatestDir() (
cd /some/dir
stat -c $'%Y\t%n' */ |
sort -rn |
cut -f2 | {
while read dir; do
[[ $dir == "summary/" ]] || break
done
echo $dir
}
)
Note that the bash wildcard */ with the trailing directory limits the results to directories only.
I execute the function in a subshell so the cd command does not affect your current directory.
I am making a script. i need to automate a portion that looks at all the files in the directory containing the string "HNAZXLCOM" in the name then take the newest file with that string in the name and put the filename into a variable.
Thanks
function latest {
if [[ $FUNCNAME == ${FUNCNAME[1]} ]]; then
unset -v x latest files
printf -v "$#"
elif (($# > 2)); then
printf '%s\n' "Usage: $FUNCNAME <glob> <varname>" 'Error: Takes at most 2 arguments. Glob defaults to *'
return 1
else
if ! shopt -q nullglob; then
typeset -f +t "$FUNCNAME"
trap 'shopt -u nullglob; trap - RETURN' RETURN
shopt -s nullglob
fi
IFS= typeset -a 'files=(${1:-*})'
typeset latest x
for x in "${files[#]}"; do
[[ -d $x || $x -ot $latest ]] || latest=$x
done
${2:+"$FUNCNAME"} "${2:-printf}" -- %s "$latest"
fi
}
latest '*HNAZXLCOM*' myVar
If I read you right
var="$(ls -t1 *HNAZXLCOM*|head -n 1)"
From man ls, the -t switch is relevant. Also see the -1 switch.
-t sort by modification time, newest first
-1 list one file per line
The -1 switch is not relevant, because ls automatically writes only one line per name when outputting to a pipe.
At a command prompt, the following function will list the 13 most recent files; eg, xt *HNAZXLCOM* would list the 13 most recent files with that string in their names, while xt by itself would list the most recent files (of any pattern) in the current working directory. Adjust the number to whatever you prefer. Some versions of head may require -n 13 instead of -13. In your application,
H=$(ls -t *HNAZXLCOM* | head -n 1)
is appropriate.
xt ()
{
date;
ls --color -Glt --color --time-style="+%Y-%m-%d %T" $* | grep -v "/" | head -13
}