Condition in bash script Post: 303038798

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Bash: if condition as variable

How can I use a variable that has the conditions for the if statement stored in it? my test script condition=" || || " if "$condition" then echo "true" else echo "false" fi output $ ./test2.sh ./test2.sh: line 3: || || : command not found false

2. Shell Programming and Scripting

Multiple condition checking in bash

Hi All, I am trying to check if two variables have value assigned to it. i am doing it like if ] then echo "Please specify either single hostname or host file for the report" usage exit fi But its not working for it.Even i specify values for both variables it dont go...

3. Programming

if condition in bash

Hi, I have meaning to include an if condition statement in my code to check the directory for existing output files and if its existing i want the program to delete it before doing the succeeding command. i just dont know the correct syntax for it. thanks much guys, this forum has indeed been very...

4. Red Hat

how to use if condition with sed command in BASH

Urgent help with bash scripting 1- i am using grep to find a string called: tinker panic 0 in a file /etc/ntp.conf if the string is not there, i want to add the strings in /etc/ntp.conf file in the first line of the file. if not do nothing or exit. 2- also i want to add # in front of the...

5. UNIX for Dummies Questions & Answers

Bash condition test at the end of string

I want to check (using bash condition test function) if string contains three spaces, ignoring last three spaces at the end of string. string_to_report='foo bar foo bar ' string_to_ignore='foo bar '

6. Shell Programming and Scripting

Add another condition to bash for when not met

In the below I can not seem to add a line that will add Not low if the statement in bold is not true or meet. I guess when the first if statement is true/meet then print low, otherwise print Not low in $(NF + 1). I am not sure how to correctly add this. Thank you :). if(low <= $2 && $2 <=...

7. Shell Programming and Scripting

Bash script if condition not executing

issue is with .txt files

8. Shell Programming and Scripting

Need Multiple checks inside if condition in a bash shell script

Hi, I need to perform the untar and rm operation if the file found is a .tar and does not have test.tar or hello.tar as the file names. Below is the loop to check the same. for tf in *.tar do if ] then found=1 ...

9. Shell Programming and Scripting

Creating a condition on a bash script

I wrote a code to find codons in a DNA string. The only problem I have is how do I make the code only work for a file with DNA. This means the file only has the characters a,c,g,t and no white space characters.

10. UNIX for Beginners Questions & Answers

Awk/bash one liner replacement for a if condition

Hi. I wrote this small bash script, i want to compare second column from file1 with file2 if a pattern matches. Files are small and I am sure that pattern occurs only once. I think this can be rewritten into a awk one liner. Appreciate if someone could give me idea. Whole NR FNR confuse me :o ...

LEARN ABOUT ULTRIX

test

test(1) General Commands Manual test(1)

Name
test - test conditional expression

Syntax
test expr
[ expr ]

Description
The command evaluates the expression expr. If the value of expr is true, the command returns a zero exit status; otherwise, it returns a
nonzero exit status. The command also returns a nonzero exit status if no arguments are specified.

Options
The following primitives are used to construct expr:

-r file Tests if the file exists and is readable.

-w file Tests if the file exists and is writable.

-f file Tests if the file exists and is not a directory.

-d file Tests if the file exists and is a directory.

-s file Tests if the file exists and has a size greater than zero.

-t [ fildes ] Tests if the open file, whose file descriptor number is fildes (1 by default), is associated with a terminal device.

-z s1 Tests if the length of string s1 is zero.

-n s1 Tests if the length of the string s1 is nonzero.

s1 = s2 Tests if the strings s1 and s2 are equal.

s1 != s2 Tests if the strings s1 and s2 are not equal.

s1 Tests if s1 is not the null string.

n1 -eq n2 Tests if number1 equals number2.

n1 -ge n2 Tests if number1 is greater than or equal to number2.

n1 -gt n2 Tests if number1 is greater than number2.

n1 -le n2 Tests if number1 is less than or equal to number2.

n1 -lt n2 Tests if number1 is less than number2.

n1 -ne n2 Tests if number1 is not equal to number2.

These primitives can be combined with the following operators:

!expr Negates evaluation of expression.

expr -a expr Tests logical and of two expressions.

expr -o expr Tests logical or of two expressions.

( expr... ) Groups expressions.

The -a operator takes precedence over the -o operator. Note that all the operators and flags are separate arguments to Note also that
parentheses are meaningful to the Shell and must be escaped.

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Bash: if condition as variable

Discussion started by: curlee2002

2. Shell Programming and Scripting

Multiple condition checking in bash

Discussion started by: kailash19

3. Programming

if condition in bash

Discussion started by: ida1215

4. Red Hat

how to use if condition with sed command in BASH

Discussion started by: lamoul