I am making a bash script where I want to find files that are equal to a variable. The equals will then be used.
I want to use "mogrify" to shrink a couple of image files that have the same name as the ones i gather from a list (similar to "dpkg -l"). It is not "dpkg -l" I am using but it is similar. My problem is that it prints all the files not just the equals. I am pretty sure this could be done with awk instead of a for-loop but I do not know how.
prog="`dpkg -l | awk '{print $1}'`"
for file in $dirone* $dirtwo*
do
if [ "basename ${file}" = "${prog}" ]; then
echo ${file} are equal
else
echo ${file} are not equal
fi
done
Could you please help me get this working?
First, I think there's a small typo. if [ "basename ${file}" =... should have backticks inside the double quotes, just like the prog=... line at the top does.
Second, if $prog is a multi-line string (like dpkg -l) you can't really compare a filename to the entire list. Instead you have to compare one item at a time to the filename.
Here's an example using dpkg and /usr/bin
#!/bin/bash
progs="`dpkg -l | awk '{print $2}'`"
for file in /usr/bin/*
do
base=`basename ${file}`
for prog in ${progs}
do
if [ "${base}" = "${prog}" ]; then
echo "${file}" matches "${prog}"
fi
done
done
The condition "$file = $prog" is a single string. You should try "$file" = "$prog" instead.
The following transcript shows the fix:
pax> ls -1 qq*
qq
qq.c
qq.cpp
pax> export xx=qq.cpp
pax> for file in qq* ; do
if [[ "${file} = ${xx}" ]] ; then
echo .....${file} equal
else
echo .....${file} not equal
fi
done
.....qq equal
.....qq.c equal
.....qq.cpp equal
pax> for file in qq* ; do
if [[ "${file}" = "${xx}" ]] ; then
echo .....${file} equal
else
echo .....${file} not equal
fi
done
.....qq not equal
.....qq.c not equal
.....qq.cpp equal
You can see in the last bit of output that only qq.cpp is shown as equal since it's the only one that matches ${xx}.
The reason you're getting true is because that's what non-empty strings will give you:
pax> if [[ "" ]] ; then
echo .....equal
fi
pax> if [[ "x" ]] ; then
echo .....equal
fi
.....equal
That's because that form is the string length checking variation. From the bash manpage under CONDITIONAL EXPRESSIONS:
string
-n string
True if the length of string is non-zero.
Update:
The new code in your question won't quite work as expected. You need:
if [[ "$(basename ${file})" = "${prog}" ]]; then
to actually execute basename and use its output as the first part of the equality check.
you can use case/esac
case "$file" in
"$prog" ) echo "same";;
esac
Related
I am trying to add a condition in a for loop to check the existence of a file as well as check for file size > 0 KB.
Period file contains monthly data:
20180101
20180201
20180301
20180401
20180501
There are individual files created for each month. Suppose a file is not created for one month, (20180201), then the loop below should terminate.
For example:
xxx_20180101.txt
xxx_20180301.txt
xxx_20180401.txt
xxx_20180501.txt
if [[ $STATUS -eq 0 ]]; then
for per in `cat ${PATH}/${PERIOD}.txt | cut -f 1 -d";"`
do
for fl in `ls -1 ${PATH}/${FILE} | grep ${per}`
do
if [[ `ls -1 $fl | wc -l` -eq 0 ]]; then
echo "File not found"
STATUS=1
else
if [[ -s "$fl" ]]; then
echo "$fl contain data.">>/dev/null
else
echo "$fl File size is 0KB"
STATUS=1
fi
fi
done
done
fi
but ls -1 $fl | wc -l is not returning 0 value when the if condition is executed.
The following is a demonstration of what a best-practices rewrite might look like.
Note:
We do not (indeed, must not) use a variable named PATH to store a directory under which we look for data files; doing this overwrites the PATH environment variable used to find programs to execute.
ls is not used anywhere; it is a tool intended to generate output for human consumption, not machines.
Reading through input is accomplished with a while read loop; see BashFAQ #1 for more details. Note that the input source for the loop is established at the very end; see the redirection after the done.
Finding file sizes is done with stat -c here; for more options, portable to platforms where stat -c is not supported, see BashFAQ #87.
Because your filename format is well-formed (with an underscore before the substring from your input file, and a .txt after that substring), we're refining the glob to look only for names matching that restriction. This prevents a search for 001 to find xxx_0015.txt, xxx_5001.txt, etc. as well.
#!/usr/bin/env bash
# ^^^^ -- NOT /bin/sh; this lets us use bash-only syntax
path=/provided/by/your/code # replacing buggy use of PATH in original code
period=likewise # replacing use of PERIOD in original code
shopt -s nullglob # generate a zero-length list for unmatched globs
while IFS=';' read -r per _; do
# populate an array with a list of files with names containing $per
files=( "$path/$period/"*"_${per}.txt" )
# if there aren't any, log a message and proceed
if (( ${#files[#]} == 0 )); then
echo "No files with $per found in $path/$period" >&2
continue
fi
# if they *do* exist, loop over them.
for file in "${files[#]}"; do
if [[ -s "$file" ]]; then
echo "$file contains data" >&2
if (( $(stat -c +%s -- "$file") >= 1024 )); then
echo "$file contains 1kb of data or more" >&2
else
echo "$file is not empty, but is smaller than 1kb" >&2
fi
else
echo "$file is empty" >&2
fi
done
done < "$path/$period.txt"
Here's a refactoring of Mikhail's answer with the standard http://shellcheck.net/ warnings ironed out. I have not been able to understand the actual question well enough to guess whether this actually solves the OP's problem.
while IFS='' read -r per; do
if [ -e "xxx_$per.txt" ]; then
echo "xxx_$per.txt found" >&2
else
echo "xxx_$per.txt not found" >&2
fi
done <periods.txt
You are over engineering here. Just iterate over content of file with periods and search each period in a list of files. Like this:
for per in `cat periods.txt`
do
if ls | grep -q "$per"; then
echo "$per found";
else
echo "$per not found"
fi
done
I have a problem with writing bash script. The problem is in comparison of strings. When I launch it, there's no errors. However in result, it is always changing the variable client.
So if for an example we have two lines in file
apple A
orange D
and if I give the who=A I expect to see in result apple, or if at D - orange
But no matter of what I choose A or D it is always giving me the result - orange
No matter of the strings, it always change the variable client, like ignoring the comparison. Please help.
while read line
do
IFS=" "
set -- $line
echo $2" "$who":"$1
if [[ "$2"="$who" ]]
then
echo "change"
client=$1
fi
done < $file
echo $client
So now I changed the code as in one of the comment below, but now the caparison always false therefore the variable client is always empty
while read -r line
do
#IFS=" "
#set -- $line
#echo $2" "$who":"$1
#if [[ "$2" = "$who" ]]
a="${line% *}"
l="${line#* }"
if [[ "$l" == "$who" ]]
then
echo "hi"
client="$a"
fi
done < $file
If you have data in a file with each line like apple D and you want to read the file and separate then items, the parameter expansion/substring extraction is the correct way to process the line. For example (note $who is taken from your problem statement):
while read -r line
do
fruit="${line% *}" # remove from end to space
letter="${line#* }" # remove from start to space
if [[ "$letter" == "$who" ]]
then
echo "change"
client="$fruit"
fi
done < $file
Short Example
Here is a quick example of splitting the words with parameter expansion/substring extraction:
#!/bin/bash
while read -r line
do
fruit="${line% *}"
letter="${line#* }"
echo "fruit: $fruit letter: $letter"
done
exit 0
input
$ cat dat/apple.txt
Apple A
Orange D
output
$ bash apple.sh <dat/apple.txt
fruit: Apple letter: A
fruit: Orange letter: D
Change if [[ "$2"="$who" ]] to
if [[ "$2" = "$who" ]]
spaces around =
Example (for clarification):
who=A
while read line
do
IFS=" "
set -- $line
echo $2" "$who":"$1
if [[ "$2" = "$who" ]]
then
echo "change"
client=$1
fi
done < file #this is the file I used for testing
echo $client
Output:
A A:apple
change
D A:orange
apple
For who=D:
A D:apple
D D:orange
change
orange
You do need spaces around that = operator.
However, I think you're facing yet another issue as you're trying to change the value of the client variable from inside the while loop (which executes in a subshell). I don't think that will work; see this quesion for details.
My code:
#!/bin/bash
content="My sms content"
nomer="My Phone number"
if [[ -n "$content" && -n "$nomer" ]]; then
echo "it passes the first filter..."
if [ "$(echo $content| awk '{print tolower($0)}')" = "My sms content" ]; then
echo "Yes it matches the content"
else
echo "the variable doesn't match the content"
fi
fi
It displays nothing when I run the code. What I want is that it displays Yes it matches the content How do I do that?
UPDATE as #BlueMoon answer I updated my code but it still says the variable doesn't match the content
I want it to match the content
As well as the problem of this passing only if both strings are empty:
if [[ -z "$content" && -z "$nomer" ]]
(you probably meant -n which is the non-empty variant), you also have the problem that a string converted to lower-case will never contain a capital M:
if [ "$(echo $content| awk '{print tolower($0)}')" = "My sms content" ]
(you probably meant "my sms content").
In any case, if you're using a relatively modern version of bash, it has case conversion built in so you don't have to use external processes. The following transcript shows the four possibilities, upper-case first, upper-case all, lower-case first and lower-case all:
pax> word='abcde' ; echo ${word^}
Abcde
pax> word='abcde' ; echo ${word^^}
ABCDE
pax> word='ABCDE' ; echo ${word,}
aBCDE
pax> word='ABCDE' ; echo ${word,,}
abcde
I gather the rationale here was that the caret ^ points up while the comma , points down. So you can simply use:
if [[ "${content,,}" == "my sms content" ]]
-z tests for being zero length. So what you're comparing is to check that both strings are empty.
This line
if [[ -z "$content" && -z "$nomer" ]]; then
says if both strings are of non-zero then do it.
What you probably meant is if both are non-empty:
if [[ -n "$content" && -n "$nomer" ]]; then
From manual:
-z string
True if the length of string is zero.
string
-n string
True if the length of string is non-zero.
I have to write a shell script that creates a file containing the name of each text files from a folder (given as parameter) and it's subfolders that contain words longer than n characters (read n from keyboard).
I wrote the following code so far :
#!/bin/bash
Verifies if the first given parameter is a folder:
if [ ! -d $1 ]
then echo $1 is not a directory\!
exit 1
fi
Reading n
echo -n "Give the number n: "
read n
echo "You entered: $n"
Destination where to write the name of the files:
destinatie="destinatie"
the actual part that i think it makes me problems:
nr=0;
#while read line;
#do
for fisier in `find $1 -type f`
do
counter=0
for word in $(<$fisier);
do
file=`basename "$fisier"`
length=`expr length $word`
echo "$length"
if [ $length -gt $n ];
then counter=$(($counter+1))
fi
done
if [ $counter -gt $nr ];
then echo "$file" >> $destinatie
fi
done
break
done
exit
The script works but it does a few more steps that i don't need.It seems like it reads some files more than 1 time. If anyone can help me please?
Does this help?
egrep -lr "\w{$n,}" $1/* >$destinatie
Some explanation:
\w means: a character that words consist of
{$n,} means: number of consecutive characters is at least $n
Option -l lists files and does not print the grepped text and -r performs a recursive scan on your directory in $1
Edit:
a bit more complete version around the egrep command:
#!/bin/bash
die() { echo "$#" 1>&2 ; exit 1; }
[ -z "$1" ] && die "which directory to scan?"
dir="$1"
[ -d "$dir" ] || die "$dir isn't a directory"
echo -n "Give the number n: "
read n
echo "You entered: $n"
[ $n -le 0 ] && die "the number should be > 0"
destinatie="destinatie"
egrep -lr "\w{$n,}" "$dir"/* | while read f; do basename "$f"; done >$destinatie
This code has syntax errors, probably leftovers from your commented-out while loop: It would be best to remove the last 3 lines: done causes the error, break and exit are unnecessary as there is nothing to break out from and the program always terminates at its end.
The program appears to output files multiple times because you just append to $destinatie. You could simply delete that file when you start:
rm "$destinatie"
You echo the numbers to stdout (echo "$length") and the file names to $destinatie (echo "$file" >> $destinatie). I do not know if that is intentional.
I found the problem.The problem was the directory in which i was searching.Because i worked on the files from the direcotry and modified them , it seems that there remained some files which were not displayed in file explorer but the script would find them.i created another directory and i gived it as parameter and it works. Thank you for your answers
.
I am trying to compare two text in Unix. I tried the below. It didn't work. In need to compare the first and last lines of a file.
firstline=`head -1 test.txt`
echo $firstline
lastline=`tail -1 test.txt`
echo $lastline
if [ $firstline == $lastline ]
then
echo "Found"
fi
Surely, am missing something. Please help.
Perhaps simpler...
bash-3.2$ if [ "$(sed -n '1p' file)" = "$(sed -n '$p' file)" ]; then
echo 'First and last lines are the same'
else
echo 'First and last lines differ'
fi
Update to answer Jan's questions.
bash-3.2$ cat file
-z
-G
bash-3.2$ if [ "$(sed -n '1p' file)" = "$(sed -n '$p' file)" ]; then
> echo 'First and last lines are the same'
> else
> echo 'First and last lines differ'
> fi
First and last lines differ
I prefer sed for grabbing the first and last lines of a file because the same command-line works on Linux, Mac OS and Solaris. The head and tail command-lines are different between Linux and Solaris.
Assuming you are using "some sort" of bourne shell, you should (a) quote the variables and (b) need to use a single =:
if [ "$firstline" = "$lastline" ]
then
echo "Found"
fi
Update In response to some comments, this will also work if $firstline is -z. Even in this case the if statement is not interpreted as if [ -z ... ], at least in the ksh (Korn Shell) or in Bash (I don't have a system with a plain bourne shell sh available).
Should be if [ "$firstline" = "$lastline" ]
If you omit double quotes it will not work if the line(s) contain white characters.
At the very least, you have to quote the variable expansions. Plus you should add prefix to avoid problems if the strings start with -. And the correct operator is =. So it should be
if [ "x$firstline" = "x$lastline" ]