Login or Register to Ask a Question and Join Our Community


UNIX for Dummies Questions & Answers

: unary operator expected

 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers : unary operator expected
# 1  
Old 02-20-2011
: unary operator expected
Hiya all,
Why do I get a :unary operator expected when I try to put a condition statement in my shell script (sh) like so and how to fix?

Code:
if [$1 = "mystring" ]; then
 
echo "say hello"
 
else
 
echo "don't say hello"
 
fi

? It seems if the script receives an argument it works but if I don't put an argument I get this error?
Last edited by Scott; 02-20-2011 at 07:04 PM.. Reason: Code tags, please!
# 2  
Old 02-20-2011
Quote:
how to fix?
By putting a space between [ and $1.
# 3  
Old 02-20-2011
Hi.

You're missing a space after [. And you should always quote input parameters and variables, especially if you don't know whether they are set / exist. Quoting literal strings / values is a question of preference.

Code:
if [ "$1" = mystring ]; then

# 4  
Old 02-20-2011
just tried it but still get the same message. its almost as if it doesn't like it when I don't input an argument?
# 5  
Old 02-20-2011
Hi Cyber,

By executing the above code
o/p was dont say helo..what u need exact o/p...
 
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Unary operator expected

In all my Googling, this usually happens when someone is comparing a variable, and that variable is unset. That doesn't appear to be the case for me... #!/bin/bash -x while read line do f=$(echo $line | tr -s ' ' | cut -d' ' -f 3) echo $f if then echo "This... (2 Replies)
Discussion started by: jnojr
2 Replies

2. UNIX for Dummies Questions & Answers

[: -gt: unary operator expected

Hi I have problem with my script. I dont now why but i don't change anything and script stop working. this is my code: #!/bin/sh for i in `ps -A | grep pocron.sh | grep -v grep | awk '{print $2}'` do COUNT=$((COUNT+1)) done ostatnie_wykonanie=`cat porader.log`... (1 Reply)
Discussion started by: fotex
1 Replies

3. Shell Programming and Scripting

unary operator expected

i=0 while Shell script reports an error "unary operator expected" pointing the above line. $i by default is 0 and holds integer value and $buf is also holding integer value. Please can some one let me know what is missing. Thanks. (1 Reply)
Discussion started by: sunrexstar
1 Replies

4. UNIX for Dummies Questions & Answers

Problem unary operator expected

I get the following error ./get_NE05: line 42: while do echo ${STRING_NAME} J=1 if ; then EXT=0$I else EXT=$I fi while do echo $I-$J #calculating last occurrence OCCURRENCE=`grep -io "${STRING_NAME}"... (3 Replies)
Discussion started by: f_o_555
3 Replies

5. UNIX for Dummies Questions & Answers

Error : -ne: unary operator expected

find . -name "*.*"|xargs grep WT:DBF_WL>> $F Wfexist=`cat $F|grep $i` echo $Wfexist if ; then echo $Wfexist echo "Workflow Exist" else touch $O chmod 777 $O echo $Wfexist echo $WfExist >> $O fi I am getting the error that -ne: unary operator expected in the line with red... (2 Replies)
Discussion started by: ritu.s
2 Replies

6. Shell Programming and Scripting

line 5: [: -gt: unary operator expected

Hello all, :confused: I am not getting this error. Pls help me. ./construct_operon.sh: line 5: #!/bin/bash # Construct Operons using gene pairs. rm -rf operons_result lines=`awk 'END {print NR}' ecoli_operons` while ; do head -1 ecoli_operons | awk '{print $1"\n"$2}' > pattern ... (5 Replies)
Discussion started by: admax
5 Replies

7. Shell Programming and Scripting

unary operator expected

Im trying to fix my /etc/weekly that rotates various logs however it does them no matter what filesize they are and i want them to only do it if there file size exceeds 2M or something. So I'm playing with a script to get the filesize using a ls -l command which works and puts the value into a... (3 Replies)
Discussion started by: timgolding
3 Replies

8. UNIX for Dummies Questions & Answers

[: =: unary operator expected

HI, while running a script, I got the below mentioned error. /bin/sh: line10 : supportedMozillaVersion() { case "$*" in *rv:1.*) return 0;; *rv:.*) return 0;; *rv:*) return 1;; Mozilla\ 1.*) return 0;; Mozilla\ .*) return 0;; *) return 1;; esac } supportedFirefoxVersion() { case... (7 Replies)
Discussion started by: bhag281
7 Replies

9. Shell Programming and Scripting

unary operator expected

hi i am trying to compare a value with value 50. but i am getting " I am using if then echo "------------" fi please help thanks in advance Satya (2 Replies)
Discussion started by: Satyak
2 Replies

10. UNIX for Dummies Questions & Answers

unary operator expected error

Hi I am doing a script like if then echo "table name dosent exist" exit fi the problem is if $table_name is null then i am getting the error Please help me Thanks in advance (2 Replies)
Discussion started by: ssuresh1999
2 Replies
Login or Register to Ask a Question