I have the following korn script:
#!/bin/ksh
TAPPDATADIR=/hp/qa02/App/IPHSLDI/Data
echo $TAPPDATADIR
if [[ls $TAPPDATADIR/zip_file_MD5_checksum*.txt | wc -l > 1]]
then
exit "asdf"
fi
When I attempt to run it I get:
/hp/qa02/App/IPHSLDI/Data
./iftest.ksh: line 7: [[ls: not found
Why isn't my if statement working?
I'm trying to see if there are multiple checksum files in the Data directory. If there are I want to exit the script.
There are several problems:
There shouldn't be any spaces around = in the assignment.
You need spaces around [[ and ]] in the if statement.
To substitute the result of a command into the test expression, you need to use backticks or $(...).
The parameter to exit should be a number, I think you just want to echo the string.
> performs string comparison, you have to use -gt to perform numeric comparison.
So the full script should be:
#!/bin/ksh
TAPPDATADIR=/hp/qa02/App/IPHSLDI/Data
echo $TAPPDATADIR
if [[ $(ls $TAPPDATADIR/zip_file_MD5_checksum*.txt | wc -l) -gt 1 ]]
then
echo "asdf"
fi
Related
my script check if the arguments are files or folders
if it is a file, he count the number of lines
after that, if the number of lines is great then 20 or less he do some instructions
the problem is in this instructionn= cat $a | wc -l
My script:
#!/usr/bin/env bash
echo 'Hello this is the test of' `date`
echo 'arguments number is ' $#
if [ $# -eq 4 ]
then
for a in $#
do
if [ -d $a ]
then
ls $a > /tmp/contenu
echo "contenu modified"
elif [ -f $a ]
then
# this instruction must set a numeric value into n
echo "my bad instruction"
n= cat $a | wc -l
echo "number of lines = " $n
# using the numeric value in a test (n must be numeric and takes the number of lines in the current file)
if [ $n -eq 0 ]
then
echo "empty file"
elif [ $n -gt 20 ]
then
echo ` head -n 10 $a `
else
cat $a
fi
else
echo "no file or directory found"
fi
done
else
echo "args number must be 4"
fi
This is the output of the execution of the incorrect instruction
my bad instruction
5
number of lines =
ExamenEx2.sh: line 19: [: -eq : opérateur unaire attendu
The line n= cat $a | wc -l is an offending instruction. Always remember that bash shell scripting is extremely case-sensitive. Your command is interpreted by the shell as having to run two separate commands
n= cat $a | wc -l
#^^ ^^^^^^^^^^^^^^
#1 2
The first part just stores an empty string to the variable n and the next prints the line count of the file stored in variable a. Notice that the shell does not throw errors for this. Because it is not violating the syntax (just the semantics are wrong). But the line count is never assigned to the variable n.
The error is seen when the conditional if [ $n -eq 0 ] is hit when you are doing a comparison with an empty variable on the LHS.
You wanted to run a command and store its output, you need command-substitution($(..)) for that. Assuming the $a contains a name of a file just do
n=$(wc -l < "$a")
Note, that I've removed the useless cat usage and piping it to wc. But wc can read from an input stream directly.
Also note that you have multiple bad practices in your script. Remember to do the following
Always double-quote the shell variables - "$#", "$#", [ -f "$a" ], [ -d "$a" ]
Don't use the `` for command-substitution, because it is not easily nestable and you might have issues related to quoting also.
You can use conditional expression [[ if you are sure if the script is running under bash in which a variable containing spaces can be used without quoting on the LHS
I'm tasked with writing a shell script that takes in a string of 6 letters and numbers and checks if they meet a certain criteria.
This is that script
FILE=$1
var=${#FILE}
if [ $var -gt 6 ] || [ $var -lt 6 ]
then
#echo $FILE "is not a valid NSID"
exit 1
else if ( echo $1 | egrep -q '^[A-Za-z]{3}\d{3}$' )
then
#echo $1 "is a valid NSID"
exit 0
else
#echo $1 "is not a valid NSID"
exit 1
fi
fi
It works. so that isn't where the problem is.
What I am trying to do is use a "wrapper" script to gather potential valid NSID's from a text file and call that script on the list of inputs. so that if I call that script within my wrapper script it will step through the text file I have given my wrapper and check if each line is valid.
FILE=$1
YES= more $FILE
if ( exec /path/to/file/is_nsid.sh $YES -eq 0 )
then
echo $FILE "is a valid NSID"
else
echo $FILE "is not a valid NSID"
fi
so if I called it with a text file called file1.txt which contained
yes123
yess12
ye1243
it would output whether each was valid or not.
The line
YES= more $FILE
Sets YES in the environment passed to the command more $FILE. That's probably not what you intended.
The line
if ( exec /path/to/file/is_nsid.sh $YES -eq 0 )
starts a subshell to execute exec /path/to/file/is_nsid.sh $YES -eq 0. (That's what the parentheses do.) exec then replaces the subshell with a process which executes
/path/to/file/is_nsid.sh $YES -eq 0
which in turn runs the script at is_nsid.sh, passing it two or three command line arguments:
the value of $YES. This could be several arguments if the value of the shell variable includes whitespace or a glob symbol, but in this case it is more likely to be nothing since $YES has not been defined.
-eq
0
Since your script only examines its first argument, that's probably equivalent to
/path/to/file/is_nsid.sh -eq
That will, presumably, terminate with a failure status code, and since the subshell has been replaced with the script execution, that will also be the return status of the subshell. (Without exec, there would be essentially no difference; the subshell's return status is that of the last command executed in the subshell. Without either the parentheses or the exec, the result would also be the same. So you could have just written if /path/to/file/is_nsid.sh $YES -eq 0 and it would produce the same incorrect result.)
What you presumably wanted to do was to read each line in the file whose name is passed as the first command-line argument to the script. You could do that as follows:
while read -r line; do
if /path/to/file/is_nsid.sh "$line"; then
echo "$line is a valid NSID"
else
echo "$line is not a valid NSID"
fi
done < "$1"
You could simplify your is_nsid script considerably. The following is equivalent:
[ $#1 -eq 6 ] && echo "$1" | egrep -q '^[A-Za-z]{3}\d{3}$'
Note that \d is a Gnu extension to egrep and should not be relied on in portable code (which I assume this is trying to be). You should use [0-9] or [[:digit:]] instead.
The length check is actually unnecessary since the regex can only match six-character lines. Personally, I'd leave it out and just use
echo "$1" | egrep -q '^[[:alpha:]]{3}[[:digit:]]{3}$'
I removed all the unnecessary if statements. If I had left them in, I would have changed else if ... then ... fi to simply elif ... then ... to avoid unnecessary if nesting.
I am learning bash. I would like to get the return value and matched line by grep at once.
if cat 'file' | grep 'match_word'; then
match_by_grep="$(cat 'file' | grep 'match_word')"
read a b <<< "${match_by_grep}"
fi
In the code above, I used grep twice. I cannot think of how to do it by grep once. I am not sure match_by_grep is always empty even when there is no matched words because cat may output error message.
match_by_grep="$(cat 'file' | grep 'match_word')"
if [[ -n ${match_by_grep} ]]; then
# match_by_grep may be an error message by cat.
# So following a and b may have wrong value.
read a b <<< "${match_by_grep}"
fi
Please tell me how to do it. Thank you very much.
You can avoid the double use of grep by storing the search output in a variable and seeing if it is not empty.
Your version of the script without double grep.
#!/bin/bash
grepOutput="$(grep 'match_word' file)"
if [ ! -z "$grepOutput" ]; then
read a b <<< "${grepOutput}"
fi
An optimization over the above script ( you can remove the temporary variable too)
#!/bin/bash
grepOutput="$(grep 'match_word' file)"
[[ ! -z "$grepOutput" ]] && (read a b <<< "${grepOutput}")
Using double-grep once for checking if-condition and once to parse the search result would be something like:-
#!/bin/bash
if grep -q 'match_word' file; then
grepOutput="$(grep 'match_word' file)"
read a b <<< "${grepOutput}"
fi
When assigning a variable with a string containing a command expansion, the return code is that of the (rightmost) command being expanded.
In other words, you can just use the assignment as the condition:
if grepOutput="$(cat 'file' | grep 'match_word')"
then
echo "There was a match"
read -r a b <<< "${grepOutput}"
(etc)
else
echo "No match"
fi
Is this what you want to achieve?
grep 'match_word' file ; echo $?
$? has a return value of the command run immediately before.
If you would like to keep track of the return value, it will be also useful to have PS1 set up with $?.
Ref: Bash Prompt with Last Exit Code
I am trying to create a "Lambda" style WHERE script.
I want lambdaWHERE to take piped input and pass it through if condition after given as arguments is met. Like xargs I use {} to represent what comes down the pipe.
I call command like:
ls -d EqAAL* | lambdaWHERE.sh -f {}/INFO_ACTIVETICK
I want the folder names passed through if they contain a file called INFO_ACTIVETICK
Here is the script:
#!/bin/sh
#set -x
ARGS=$*
while read i
do
CMD=`echo $ARGS | sed 's/{}/'$i'/g'`
if [[ $CMD ]]
then
echo $i
fi
done
But when I run it a mysterious "-n" appears...
$ ls -d EqAAL* | /q/lambdaWHERE.sh -f {}/INFO_ACTIVETICK
+ ARGS='-f {}/INFO_ACTIVETICK'
+ read i
++ echo -f '{}/INFO_ACTIVETICK'
++ sed 's/{}/EqAAL-1m/g'
+ CMD='-f EqAAL-1m/INFO_ACTIVETICK'
+ [[ -n -f EqAAL-1m/INFO_ACTIVETICK ]]
+ echo EqAAL-1m
EqAAL-1m
+ read i
How can I get the bit in the [[ ]] correct?
You were quite close. you only need to switch to the standard POSIX [ $CMD ] and it will work.
The main difference between using [[ $CMD ]] and [ $CMD ] is that the first has fewer surprises and you need not quote variables. That also means that a variable is though of as one token and cannot have a whole expression in it like you are trying. [ $CMD ] however works the same way as the original shell where [ was just a command an thus need explicit quotations in order to interpret something with spaces as one argument.
There is a relevant question about the differences between [[ ...]] and [ ..]
I wrote a bash script that uploads a file on my home server. It gets activated from a folder action script using applescript. The setup is the folder on my desktop is called place_on_server. Its supposed to have an internal file structure exactly like the folder I want to write to: /var/www/media/
usage goes something like this:
if directory etc added to place_on_server: ./upload DIR etc
if directory of directory: etc/movies ./upload DIR etc movies //and so on
if file to place_on_server: ./upload F file.txt
if file in file in place_on_server ./upload F etc file.txt //and so on
for creating a directory its supposed to execute a command like:
ssh root#192.168.1.1<<EOF
cd /var/www/media/wherever
mkdir newdirectory
EOF
and for file placement:
rsync -rsh='ssh -p22' file root#192.168.1.1:/var/www/media/wherever
script:
#!/bin/bash
addr=$(ifconfig -a | ./test)
if ($# -le "1")
then
exit
elif ($1 -eq "DIR")
then
f1="ssh -b root#$addr<<EOF"
list = "cd /var/www/media\n"
if($# -eq "2")
then
list=list+"mkdir $2\nEOF\n"
else
num=2
i=$(($num))
while($num < $#)
do
i=$(($num))
list=list+"mkdir $i\n"
list=list+"cd $i\n"
$num=$num+1
done
fi
echo $list
elif ($1 -eq "F")
then
#list = "cd /var/www/media\n"
f2="rsync -rsh=\'ssh -p22\' "
f3 = "root#$addr:/var/www/media"
if($# -eq "2")
then
f2=f2+$2+" "+f3
else
num=3
i=$(($num))
while($num < $#)
do
i=$(($num))
f2=f2+"/"+$i
$num=$num+1
done
i=$(($num))
f2=f2+$i+" "+$f3
fi
echo $f2
fi
exit
output:
(prompt)$ ./upload2 F SO test.txt
./upload2: line 3: 3: command not found
./upload2: line 6: F: command not found
./upload2: line 25: F: command not found
So as you can see I'm having issues handling input. Its been awhile since I've done bash. And it was never extensive to begin with. Looking for a solution to my problem but also suggestions. Thanks in advance.
For comparisons, use [[ .. ]]. ( .. ) is for running commands in subshells
Don't use -eq for string comparisons, use =.
Don't use < for numerical comparisons, use -lt
To append values, f2="$f2$i $f3"
To add line feeds, use $'\n' outside of double quotes, or a literal linefeed inside of them.
You always need "$" on variables in strings to reference them, otherwise you get the literal string.
You can't use spaces around the = in assignments
You can't use $ before the variable name in assignments
To do arithmetics, use $((..)): result=$((var1+var2))
For indirect reference, such as getting $4 for n=4, use ${!n}
To prevent word splitting removing your line feeds, double quote variables such as in echo "$line"
Consider writing smaller programs and checking that they work before building out.
Here is how I would have written your script (slightly lacking in parameter checking):
#!/bin/bash
addr=$(ifconfig -a | ./test)
if [[ $1 = "DIR" ]]
then
shift
( IFS=/; echo ssh "root#$addr" mkdir -p "/var/www/media/$*"; )
elif [[ $1 = "F" ]]
then
shift
last=$#
file=${!last}
( IFS=/; echo rsync "$file" "root#$addr:/var/www/media/$*" )
else
echo "Unknown command '$1'"
fi
$* gives you all parameters separated by the first character in $IFS, and I used that to build the paths. Here's the output:
$ ./scriptname DIR a b c d
ssh root#somehost mkdir -p /var/www/media/a/b/c/d
$ ./scriptname F a b c d somefile.txt
rsync somefile.txt root#somehost:/var/www/media/a/b/c/d/somefile.txt
Remove the echos to actually execute.
The main problem with your script are the conditional statements, such as
if ($# -le "1")
Despite what this would do in other languages, in Bash this is essentially saying, execute the command line $# -le "1" in a subshell, and use its exit status as condition.
in your case, that expands to 3 -le "1", but the command 3 does not exist, which causes the error message
./upload2: line 3: 3: command not found
The closest valid syntax would be
if [ $# -le 1 ]
That is the main problem, there are other problems detailed and addressed in that other guy's post.
One last thing, when you're assigning value to a variable, e.g.
f3 = "root#$addr:/var/www/media"
don't leave space around the =. The statement above would be interpreted as "run command f3 with = and "root#$addr:/var/www/media" as arguments".