This question already has answers here:
Why should there be spaces around '[' and ']' in Bash?
(5 answers)
using OR in shell script
(2 answers)
Closed 7 months ago.
here is my simple script prova.sh:
#!/bin/bash
echo "\$# = [$#]"
echo "\$1 = [$1]"
if [ $# -ge 2 || $1="-h" ]
then
echo "#########################################################################"
echo -e "usage: $0 \t launches the program only"
echo -e " $0 -s\t shows the command fired and launches the program"
echo -e " $0 -so\t shows only the command fired"
echo -e " $0 -h\t shows this guide"
echo "#########################################################################"
exit 0
fi
command="ls -la"
if test "$1"="-so" || "$1"="-s"
then
echo "Fired command:"
echo $command
fi
if test "$1"!="-so"
then
$command
fi
here is the output:
$> ./prova.sh -h
$# = [1]
$1 = [-h]
./prova.sh: row 6 : [: "]" missing
./prova.sh: row6: -h=-h: command not found
Fired command:
ls -l
totale 4
-rwxrw-r--. 1 user user 632 20 lug 16.13 prova.sh
I expected just the help
you need to close every test using single brackets, the shell way, if [ $# -ge 2 ] || [ $1 = "-h" ]; then ... this will fix it. If you still use single brackets way, is safe to enclose you variables with double quotes, so if they are empty, you are safe, like this if [ "$#" -ge 2 ] || [ "$1" = "-h" ]; then ... or you can just put them inside a double bracket, and bash will handle this for you if [[ $# -ge 2 || $1 = "-h" ]]; then ...
Related
This question already has answers here:
An example of how to use getopts in bash
(8 answers)
Closed 7 months ago.
Can some please help how to pass named command line arguments to my shell script. Something like below.
./myOwnShellScript.sh -name Thor -tool Hammer
Below is one way to implement
#!/bin/bash
#################################################################################################
# Script name - myOwnShellScript.sh
# Description - This script is used to implement my own logic.
# Author - Tony
#################################################################################################
function usage(){
echo "Here is usage..."
echo "./myOwnShellScript.sh -name <<Name of your hero>> -tool <<your hero's tool>>"
}
function paramMap(){
declare -A params=( ["name"]="name" ["tool"]="tool" )
paramVarName="${params[${1}]}"
[ -z "${paramVarName}" ] && echo "info" || echo "${paramVarName}"
}
####################################################################################
#----------------------------------------------------------------------------------#
# Main starts, the script execution starts here. #
#----------------------------------------------------------------------------------#
####################################################################################
export TERM="xterm"
clear
trap "exit 1" TERM
export TOP_PID=$$
CURR_TIME=$(date +"%Y-%m-%d-%T")
echo -e "\n**********************************************"
echo -e "\n myOwnShellScript.sh Script Started ${CURR_TIME}"
echo -e "\n**********************************************"
##################################################################################################
# Variable Declaration
##################################################################################################
#Read command line parameters and set script variables.
while [ $# -gt 0 ]; do
if [[ $1 == *"-"* ]]; then
v="${1/-/}"
p=$(paramMap ${v})
paramValue=$([ -z "$2" ] && echo "1" || echo "$2")
declare $p="${paramValue}"
fi
shift
done
echo "Here is your hero ${name}"
echo "His tool is ${tool}"
have some problem with shell script.
In our office we set up only few commands, that available for devs when they are trying ssh to server. It is configured with help of .ssh/authorized_keys file and available command for user there is bash script:
#!/bin/sh
if [[ $1 == "--help" ]]; then
cat <<"EOF"
This script has the purpose to let people remote execute certain commands without logging into the system.
For this they NEED to have a homedir on this system and uploaded their RSA public key to .ssh/authorized_keys (via ssh-copy-id)
Then you can alter that file and add some commands in front of their key eg :
command="/usr/bin/dev.sh",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty
The user will do the following : ssh testuser#server tail testserver.example.com/2017/01/01/user.log
EOF
exit 0;
fi
# set global variable
set $SSH_ORIGINAL_COMMAND
# set the syslog path where the files can be found
PATH="/opt/syslog/logs"
# strip ; or any other unwanted signs out of the command, this prevents them from breaking out of the setup command
if [[ $1 != "" ]]; then
COMMAND=$1
COMMAND=${COMMAND//[;\`]/}
fi
if [[ $2 != "" ]]; then
ARGU1=$2
ARGU1=${ARGU1//[;\`]/}
fi
if [[ $3 != "" ]]; then
ARGU2=$3
ARGU2=${ARGU2//[;\`]/}
fi
if [[ $4 != "" ]]; then
ARGU3=$4
ARGU3=${ARGU3//[;\`]/}
fi
# checking for the commands
case "$COMMAND" in
less)
ARGU2=${ARGU1//\.\./}
FILE=$PATH/$ARGU1
if [ ! -f $FILE ]; then
echo "File doesn't exist"
exit 1;
fi
#echo " --------------------------------- LESS $FILE"
/usr/bin/less $FILE
;;
grep)
if [[ $ARGU2 == "" ]]; then
echo "Pls give a filename"
exit 1
fi
if [[ $ARGU1 == "" ]]; then
echo "Pls give a string to search for"
exit 1
fi
ARGU2=${ARGU2//\.\./}
FILE=$PATH/$ARGU2
/usr/bin/logger -t restricted-command -- "------- $USER Executing grep $ARGU1 \"$ARGU2\" $FILE"
if [ ! -f $FILE ]; then
echo "File doesn't exist"
/usr/bin/logger -t restricted-command -- "$USER Executing $#"
exit 1;
fi
/bin/grep $ARGU1 $FILE
;;
tail)
if [[ $ARGU1 == "" ]]; then
echo "Pls give a filename"
exit 1
fi
ARGU1=${ARGU1//\.\./}
FILE=$PATH/$ARGU1
if [ ! -f $FILE ]; then
echo "File doesn't exist"
/usr/bin/logger -t restricted-command -- "$USER Executing $# ($FILE)"
exit 1;
fi
/usr/bin/tail -f $FILE
;;
cat)
ARGU2=${ARGU1//\.\./}
FILE=$PATH/$ARGU1
if [ ! -f $FILE ]; then
echo "File doesn't exist"
exit 1;
fi
/bin/cat $FILE
;;
help)
/bin/cat <<"EOF"
# less LOGNAME (eg less testserver.example.com/YYYY/MM/DD/logfile.log)
# grep [ARGUMENT] LOGNAME
# tail LOGNAME (eg tail testserver.example.com/YYYY/MM/DD/logfile.log)
# cat LOGNAME (eg cat testserver.example.com/YYYY/MM/DD/logfile.log)
In total the command looks like this : ssh user#testserver.example.com COMMAND [ARGUMENT] LOGFILE
EOF
/usr/bin/logger -t restricted-command -- "$USER HELP requested $#"
exit 1
;;
*)
/usr/bin/logger -s -t restricted-command -- "$USER Invalid command $#"
exit 1
;;
esac
/usr/bin/logger -t restricted-command -- "$USER Executing $#"
The problem is next:
when i try to exec some command, it takes only first argument, if i do recursion in files by using {n,n1,n2} - it doesn't work:
[testuser#local ~]$ ssh testuser#syslog.server less srv1838.example.com/2017/02/10/local1.log |grep 'srv2010' | wc -l
0
[testuser#local ~]$ ssh testuser#syslog.server less srv2010.example.com/2017/02/10/local1.log |grep 'srv2010' | wc -l
11591
[testuser#local ~]$ ssh testuser#syslog.server less srv{1838,2010}.example.com/2017/02/10/local1.log |grep 'srv2010' | wc -l
0
[testuser#local ~]$ ssh testuser#syslog.server less srv{2010,1838}.example.com/2017/02/21/local1.log |grep 'srv2010' | wc -l
11591
Could someone help me, how can i parse\count command arguments to make it work?
Thank you and have a nice day!
The number of arguments for a bash script would be $#. As a quick example:
#!/bin/bash
narg=$#
typeset -i i
i=1
while [ $i -le $narg ] ; do
echo " $# $i: $1"
shift
i=$i+1
done
gives, for bash tst.sh a b {c,d}
4 1: a
3 2: b
2 3: c
1 4: d
In your script, the command to execute (cat, less, ...) gets explicitly only the second argument to the script. If you want to read all arguments, you should do something like this (note: only a hint, removed all sorts of checks etc..)
command="$1"
shift
case $command in
(grep) pattern="$1"
shift
while [ $# -gt 0 ] ; do
grep "$pattern" "$1"
shift
done
;;
esac
note: added some quotes as comment suggested, but, being only a hint, you should carefully look at quoting and your checks in your own script.
Less command working now:
case "$COMMAND" in
less)
if [[ $ARGU1 == "" ]]; then
echo "Pls give a filename"
exit 1
fi
FILES_LIST=${#:2}
FILE=(${FILES_LIST//\.\./})
for v in "${FILE[#]}";do
v=${v//[;\']/}
if [ ! -f $v ]; then
echo "File doesn't exist"
fi
/usr/bin/less $PATH/$v
done;;
tail command works too with 2 and more files, but i can't execute tail -f command on two files unfortunately.
I am trying to check if a user types multiple arguments in a command line using case and if/else statements. What's wrong is that I keep getting the default case instead of the same command, but with 2 more arguments. For instance, one of my conditions is:
del)
if [ -z "$2" ] || [ -z "$3" ]
then
echo "Usage: removes a file"
else
echo "using Bash command: rm $2 $3"
rm $2 $3
echo done
fi
prints the first condition, but if I type, say, del aaa bbb, I get the default case, which is:
echo "ERROR: Unrecognized command"
I'm also using this to read a user's input, if that helps.
read -p "wcl> " -r wcl $2 $3
I don't really know if there's a better way to solve this without scrapping all my code and starting from scratch.
This is the full code:
#!/bin/bash
#use read command
echo Welcome to the Windows Command Line simulator!
echo Enter your commands below
while true
do
read -p "wcl> " -r wcl $2 $3
case $wcl in
dir)
echo "using Bash command: ls $2 $3"
ls
continue
;;
copy)
FILE="$2"
if [ "$#" -ne 3 ]
then
echo "Usage: copy sourcefile destinationfile"
else
echo "using Bash command: cp $2 $3"
if [ -f "$FILE" ]
then
cp $2 $3
else
echo "cannot stat $FILE: No such file or directory">&2
fi
echo done
fi
continue
;;
del)
if [ -z "$2" ] || [ -z "$3" ]
then
echo "Usage: removes a file"
else
echo "using Bash command: rm $2 $3"
rm $2 $3
echo done
fi
continue
;;
move)
if [ -z "$2" ] || [ -z "$3" ]
then
echo "Usage: moves a file to another file name and location"
else
echo "using Bash command: mv $2 $3"
mv $2 $3
echo done
fi
continue
;;
rename)
if [ -z "$2" ] || [ -z "$3" ]
then
echo "Usage: renames a file"
else
echo "using Bash command: mv $2 $3"
mv $2 $3
echo done
fi
continue
;;
ipconfig)
ifconfig eth0 | grep "inet addr" | cut -d ':' -f 2 | cut -d ' ' -f 1
continue
;;
exit)
echo "Goodbye"
exit 1
;;
^c)
echo "Goodbye"
exit 1
;;
*)
echo "ERROR: Unrecognized command"
continue
esac
done
You can't use read to set the positional parameters, although it isn't clear why you would need to here. Just use regular parameters.
while true
do
read -p "wcl> " -r wcl arg1 arg2
case $wcl in
dir)
echo "using Bash command: ls $arg1 $arg2"
ls "$arg1" "$arg2"
continue
;;
# ...
esac
done
The way read -r wcl $2 $3 is executed is that $2 and $3 are first expanded to give names that read will use to set variables. If those aren't set, then the command reduces to read -r wcl, and so your entire command line is assigned to the variable wcl, not just the command.
However, read by itself is not going to do the same parsing that the shell already does, if you goal is to write your own shell.
If you are really using bash, you can insert the words you read into positional parameters through an array. (You could also just leave them in the array, but the syntax for referring to positional parameters is simpler.)
# -a: read the successive words into an array
read -r -p "wcl> " -a params
# set the positional parameters to the expansion of the array
set -- "${params[#]}"
wcl=$1 # Or you could do the case on "$1"
This will also set $# to the number of words read, as a side-effect of setting the positional parameters.
As #chepner points outs, the read is problematic: It simply splits the input into whitespace-separated words, without respecting quotes, backslashes, and whatever other shell metacharacters you might want to implement. Doing a full bash-style parse of a command-line in bash itself would be quite a difficult exercise.
I have a simple script in Bash to read a number in a file and then compare it with a different threshold. The output is this:
: integer expression expected
: integer expression expected
OK: 3
My code is this:
#!/bin/bash
wget=$(wget http://10.228.28.8/ -O /tmp/wget.txt 2>/dev/null)
output=$(cat /tmp/wget.txt | awk 'NR==6')
#output=7
echo $output
if [ $output -ge 11 ];then
echo "CRITICAL: $output"
exit 2
elif [ $output -ge 6 ] && [ $output -lt 11 ];then
echo "WARNING: $output"
exit 1
else
echo "OK: $output"
exit 0
fi
rm /tmp/wget.txt
I know what is the problem, I know that I'm reading a string and I try to compare a int. But I don't know how can I do to read this file and convert the number to read in a int var..
Any ideas?
The problem occurs when $output is the empty string; whether or not you quote the expansion (and you should), you'll get the integer expression required error. You need to handle the empty string explictly, with a default value of zero (or whatever default makes sense).
wget=$(wget http://10.228.28.8/ -O /tmp/wget.txt 2>/dev/null)
output=$(awk 'NR==6' < /tmp/get.txt)
output=${output:-0}
if [ "$output" -ge 11 ];then
echo "CRITICAL: $output"
exit 2
elif [ "$output" -ge 6 ];then
echo "WARNING: $output"
exit 1
else
echo "OK: $output"
exit 0
fi
(If you reach the elif, you already know the value of $output is less than 11; there's no need to check again.)
The problem also occurs, and is consistent with the error message, if output ends with a carriage return. You can remove that with
output=${output%$'\r'}
There are a couple of suggestions from my side regarding your code.
You could explicitly tell bash the output is an integer
declare -i output # See [1]
Change
output=$(cat /tmp/wget.txt | awk 'NR==6') # See [2]
may be better written as
output=$(awk 'NR==6' /tmp/wget.txt )
Change
if [ $output -ge 11 ]
to
if [ "0$output" -ge 11 ] # See [4]
or
if (( output >= 11 )) # Better See [3]
References
Check bash [ declare ].
Useless use of cat. Check [ this ]
Quoting [ this ] answer :
((...)) enable you to omit the dollar signs on integer and array variables and include spaces around operators for readability. Also empty variable automatically defaults to 0 in such a statement.
The zero in the beginning of "0$output" help you deal with empty $output
Interesting
Useless use of cat is a phrase that has been resounding in SO for long. Check [ this ]
[ #chepner ] has dealt with the empty output fiasco using [ bash parameter expansion ] in his [ answer ], worth having a look at.
A simplified script:
#!/bin/bash
wget=$(wget http://10.228.28.8/ -O /tmp/wget.txt 2>/dev/null)
output=$(awk 'NR==6' </tmp/wget.txt )
output="$(( 10#${output//[^0-9]} + 0 ))"
(( output >= 11 )) && { echo "CRITICAL: $output"; exit 2; }
(( output >= 6 )) && { echo "WARNING: $output"; exit 1; }
echo "OK: $output"
The key line to cleanup any input is:
output="$(( 10#${output//[^0-9]} + 0 ))"
${output//[^0-9]} Will leave only digits from 0 to 9 (will remove all non-numeric chars).
10#${output//[^0-9]} Will convert output to a base 10 number.
That will correctly convert numbers like 0019
"$(( 10#${output//[^0-9]} + 0 ))" Will produce a zero for a missing value.
Then the resulting number stored in output will be compared to limits and the corresponding output will be printed.
In BASH, It is a good idea to use double brackets for strings:
if [[ testing strings ]]; then
<whatever>
else
<whatever>
fi
Or double parenthesis for integers:
if (( testing ints )); then
<whatever>
else
<whatever>
fi
For example try this:
var1="foo bar"
if [ $var1 == 'foo bar' ]; then
echo "ok"
fi
Result:
$ bash: [: too many arguments
Now, this:
var2="foo bar"
if [[ $a == "foo bar" ]]; then
echo "ok"
fi
Result:
ok
For that, your code in BASH:
if [[ $output -ge 11 ]]; then
echo "CRITICAL: $output"
exit 2
elif [[ $output -ge 6 ]]; then
echo "WARNING: $output"
exit 1
else
echo "OK: $output"
exit 0
fi
Closed. This question needs details or clarity. It is not currently accepting answers.
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Closed 7 years ago.
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Task 1:
If the Time is AM, print "It is Morning". If it is PM, print "It is not morning".
Task 2:
Given 2 arguments passed to the script.
Validate that 2 arguments have been submitted. If three arguments have not been provided, print "Must Supply 2 Arguments" and exit the script
Argument 1: Should be a directory (needs validated). If this does not exist, print "Directory: directory, does not exist" and exit the script
Argument 2: Should be a file (needs validated). If this does not exist, print "File: filename, does not exist" and exit the script.
If all arguments are valid, print "Given valid: filename and directory"
This is what I have so far
echo "James DuBois: 555555 - Task 1"
TIME=$(date "+%H")
if [ $TIME -lt 12 ]; then
echo "morning"
else
echo "not morning"
fi
echo "Task 2"
[ -d "$1" ] || exit
[ -d "$2" ] || exit
[ $# == 2 ] || exit
echo "arg1: $1"
echo "arg2: $2"
James, BASH is a wonderful, flexible shell. It has its warts, but if you need to do anything having to do with Linux system administration, etc.., you can do it in bash. Your tasks are to familiarize you with using conditional expressions (tests). There are tests for just about anything you need. That's why I pointed you to the CONDITIONAL EXPRESSIONS part of man bash.
Your second task requires the input of a filename so you can test it. I presume it is intended to be passed as an argument to your script (called positional parameters). Here is one way to approach the test. Note: I have interchanged output routines echo and printf intentionally for your benefit (printf being a bit more robust). Take a look at the following and let me know what questions you have:
#!/bin/bash
# My first script
#
# echo & printf are used at random below -- intentionally
#
[ -z $1 ] && { # validate at least 1 argument given on command line
printf "error: insufficient input. usage: %s filename\n" "${0##*/}"
exit 1
}
printf "\nJames DuBois: 5555555\n\n Task 1\n\n"
TIME=$(date "+%H")
## test for time of date: morning/not morning
if [ $TIME -lt 12 ]; then
printf " morning - time for coffee\n"
else
echo " not morning - time for scotch"
fi
echo -e "\n Task 2\n"
printf "Testing whether '%s' is a valid file.\n\n" "$1"
## test for file using compound commands
[ -f "$1" ] && echo -e " file found: '$1'\n" || printf " file not found: '%s'\n\n" "$1"
echo -e "Second test whether '$1' is a valid file.\n"
## test for file using if; then; else; fi
if [ -f "$1" ]; then
printf " file found: '%s'\n\n" "$1"
else
echo -e " file not found: '$1'\n"
fi
exit 0
Use/Output
$ bash ~/scr/tmp/stack/morningfile.sh
error: insufficient input. usage: morningfile.sh filename
$ bash ~/scr/tmp/stack/morningfile.sh mtrx_simple_dyn.c
James DuBois: 5555555
Task 1
not morning - time for scotch
Task 2
Testing whether 'mtrx_simple_dyn.c' is a valid file.
file found: 'mtrx_simple_dyn.c'
Second test whether 'mtrx_simple_dyn.c' is a valid file.
file found: 'mtrx_simple_dyn.c'
$ bash ~/scr/tmp/stack/morningfile.sh dog.c
James DuBois: 5555555
Task 1
not morning - time for scotch
Task 2
Testing whether 'dog.c' is a valid file.
file not found: 'dog.c'
Second test whether 'dog.c' is a valid file.
file not found: 'dog.c'
This will have some additional advantages while doing the same thing in task 2:
echo "Task 2"
[[ -d $1 && ! -L $1 && -f $2 && ! -L $2 ]] || exit
printf "%s\n" "arg1: $1" "arg2: $2"
It checks for symbolic links with the -L option.
[[ ]] has some advantages over [ ] like dealing with white spaces without the need for quoting variables.
If you want to print messages while checking for directory and file:
[[ ! -d $1 || -L $1 ]] && echo "Directory doesn't exist" && exit
[[ ! -f $2 || -L $2 ]] && echo "File doesn't exist" && exit
printf "%s\n" "arg1: $1" "arg2: $2"