Sponsored Content
Top Forums Shell Programming and Scripting Code checking for all values in the same if statement. Post 46757 by Perderabo on Friday 23rd of January 2004 08:30:18 PM
Old 01-23-2004
The brackets seems to be properly surrounded by whitespace. But the equals sign is not. This is legal:
[ "$string" ]

and it test whether or not string is null. If effect that what is being tested in this code.

Even when the spaces are added, the code will fail is $1 is null. There must be three things inside the brackets.

"$1" would solve that.

Late again... Smilie
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

checking valid values in variable

I'm using the following in my script. if echo $cpuidle |/usr/bin/egrep ; then when I issue this statement it issues the value of the variable back to stdout which ends up in my output file. Is there a better way to write this? I'm using ksh on solaris 9. (3 Replies)
Discussion started by: MizzGail
3 Replies

2. Shell Programming and Scripting

Error code checking

I'm trying to create a directory from my Perl script. Only if the there was an error I want to let the user know about it. So if the folder exists is ok. This is what I think should work: `mkdir log 2>/dev/null`; if($? == 0 || $? == errorCodeForFileExists) { everyting is fine } else {... (3 Replies)
Discussion started by: jepombar
3 Replies

3. UNIX for Dummies Questions & Answers

checking parameter values passed to script

Hi, I will pass 3 parameters for a script.I have to check the file name and create a new file name with time stamp. the parameters which i'm passing are /dir/stg/filename.txt /dir/path/head.txt /dir/path/tail.txt Now i have to check filename like : if it is a.txt i have to create... (2 Replies)
Discussion started by: ammu
2 Replies

4. Shell Programming and Scripting

checking the return code

hi i have a file, i am reading line by line and checking a line contains a string , `grep "Change state" $LINE` if then echo "The line contains---" else echo "The line does not contains---" i need to check the return code , but i am getting an error ... (4 Replies)
Discussion started by: Satyak
4 Replies

5. Shell Programming and Scripting

Iterative statement to cut values from a line

Hi I am new to shell scripting and trying to get values from a text file, I have a text file with values seperated with "|". like aga|120220090525|120220090525|120220090525|120220090530 bab|120220090530|120220090530|120220090535|120220090535|120220090535... (4 Replies)
Discussion started by: mannepalli
4 Replies

6. Shell Programming and Scripting

SH if statement using FLOAT values

Today I spent longer than I'd like to admit figuring out how to write a Bourne shell IF statement that tests a FLOAT value before executing a block of statements. Here's the solution I found, which invokes bc. Hope this will come in handy for someone: value = testval = if then body... (5 Replies)
Discussion started by: sjepsen
5 Replies

7. Shell Programming and Scripting

Checking the Column values in a file.

Hi All, I have a file that has ~2.9Millions lines with 32 columns respectively. The columns numbers 23,27 are the primary Keys for the file. The fields are delimited by TAB. I need to check the condition If Column number: 20 is NOT NULL Column number: 21 is not 0 Column number: 22 is... (7 Replies)
Discussion started by: filter
7 Replies

8. Shell Programming and Scripting

code checking

i was just wondering how would you check , beside the lock method, if an instance of another code is already running and if it is then output a message to the user saying the program is already running and exit!! the code is in BOURNE SHELLL!!! thanks in advance!! (3 Replies)
Discussion started by: bshell_1214
3 Replies

9. Shell Programming and Scripting

Checking for duplicate code

I have a short line of code that checks very rudimentary for duplicate code: sort myfile.cpp | uniq -c | grep -v "^.*1 " | grep -v "}" It sorts the file, counts occurrences of each line, removes single occurrences and removes the ubiquitous closing brace. The language is C++, but is easily... (3 Replies)
Discussion started by: figaro
3 Replies

10. Shell Programming and Scripting

Pass values to case statement in a function korn shell

I'm in the process of writng a function that consists of a case statement is there a way of calling the function and passing a value to it? ie function1 () { case opt1 do ..... opt2 do..... esac } function opt1 I'm aware the syntax is not correct, but you get the general idea. (1 Reply)
Discussion started by: squrcles
1 Replies
test(1sh5)																test(1sh5)

Name
       test - condition evaluation command

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.  The following primitives are  used	to
       construct expr:

       -r file	      True if file exists and is readable.

       -w file	      True if file exists and is writable.

       -x file	      True if file exists and is executable.

       -f file	      True if file exists and is a regular file.

       -d file	      True if file exists and is a directory.

       -c file	      True if file exists and is a character special file.

       -b file	      True if file exists and is a block special file.

       -p file	      True if file exists and is a named pipe (fifo).

       -u file	      True if file exists and its set-user-ID bit is set.

       -g file	      True if file exists and its set-group-ID bit is set.

       -k file	      True if file exists and its sticky bit is set.

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

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

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

       -n s1	      True if the length of the string s1 is non-zero.

       s1 = s2	      True if strings s1 and s2 are identical.

       s1 != s2       True if strings s1 and s2 are not identical.

       s1	      True if s1 is not the null string.

       n1 -eq n2      True  if	the integers n1 and n2 are algebraically equal.  Any of the comparisons -ne, -gt, -ge, -lt, and -le may be used in
		      place of -eq.

       These primitives can be combined with the following operators:

       !	      unary negation operator.

       -a	      binary and operator.

       -o	      binary or operator (-a has higher precedence than -o).

       ( expr )       parentheses for grouping.

       Note that all the operators and flags are separate arguments to the command.  Note also that parentheses are meaningful to  the	Shell  and
       must  be  escaped.   In the form of the command that uses square brackets ([]), instead of the word test, the brackets must be delimited by
       blanks.

See Also
       find(1), sh5(1), test(1)

																	test(1sh5)
All times are GMT -4. The time now is 03:24 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy