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 Replies)
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... (6 Replies)
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... (2 Replies)
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 ' (8 Replies)
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 <=... (5 Replies)
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
... (1 Reply)
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. (3 Replies)
I want get from user and pass these parameters to bash script. script should copy files in user home directory.
FYI: each file might be exist or not, might be one of them exist or four of them.
Here is my script, it always copy file1 and seems only one of them execute!
#!/bin/bash
for... (6 Replies)
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
... (6 Replies)
Discussion started by: ctrld
6 Replies
LEARN ABOUT REDHAT
delete
DELETE(7) SQL Commands DELETE(7)NAME
DELETE - delete rows of a table
SYNOPSIS
DELETE FROM [ ONLY ] table [ WHERE condition ]
INPUTS
table The name (optionally schema-qualified) of an existing table.
condition
This is an SQL selection query which returns the rows which are to be deleted.
Refer to the SELECT statement for further description of the WHERE clause.
OUTPUTS
DELETE count
Message returned if items are successfully deleted. The count is the number of rows deleted.
If count is 0, no rows were deleted.
DESCRIPTION
DELETE removes rows which satisfy the WHERE clause from the specified table.
If the condition (WHERE clause) is absent, the effect is to delete all rows in the table. The result is a valid, but empty table.
Tip: TRUNCATE [truncate(7)] is a PostgreSQL extension which provides a faster mechanism to remove all rows from a table.
By default DELETE will delete tuples in the table specified and all its sub-tables. If you wish to only update the specific table men-
tioned, you should use the ONLY clause.
You must have write access to the table in order to modify it, as well as read access to any table whose values are read in the condition.
USAGE
Remove all films but musicals:
DELETE FROM films WHERE kind <> 'Musical';
SELECT * FROM films;
code | title | did | date_prod | kind | len
-------+---------------------------+-----+------------+---------+-------
UA501 | West Side Story | 105 | 1961-01-03 | Musical | 02:32
TC901 | The King and I | 109 | 1956-08-11 | Musical | 02:13
WD101 | Bed Knobs and Broomsticks | 111 | | Musical | 01:57
(3 rows)
Clear the table films:
DELETE FROM films;
SELECT * FROM films;
code | title | did | date_prod | kind | len
------+-------+-----+-----------+------+-----
(0 rows)
COMPATIBILITY
SQL92
SQL92 allows a positioned DELETE statement:
DELETE FROM table WHERE
CURRENT OF cursor
where cursor identifies an open cursor. Interactive cursors in PostgreSQL are read-only.
SQL - Language Statements 2002-11-22 DELETE(7)