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Full Discussion: grep in a variable
Top Forums Shell Programming and Scripting grep in a variable Post 302648307 by gary_w on Tuesday 29th of May 2012 03:27:31 PM
Old 05-29-2012
grep not finding the pattern is not really an error, but grep succeeding in finding nothing. Just test for null before using it. Break it into separate steps depending on how granular you need to get to handle various conditions. It depends on your requirements. For instance, do you halt if $var1 is not set? Halt if $var1 is set but not found in the log? i.e. only grep if $var1 is not null:
Code:
#  Test to see if $var1 is null
if [[ -v "$var1" ]]; then  # Make sure to quote it so the test "sees" the null.
  echo '$var1 is null'
  # Code for var1 being null goes here.
else
  search=`grep $var1 /conf/usage.log`
  if [[ -v "$search" ]]; then  
    echo "[$var1] is not found"
    # Code for var1 not found goes here
  else  
    var2=`echo $search | tail -1 | cut -d " " -f 2` 
  fi
fi

 

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MYSQLI_STMT_BIND_RESULT(3)						 1						MYSQLI_STMT_BIND_RESULT(3)

mysqli_stmt::bind_result - Binds variables to a prepared statement for result storage

       Object oriented style

SYNOPSIS
bool mysqli_stmt::bind_result (mixed &$var1, [mixed &$...]) DESCRIPTION
Procedural style bool mysqli_stmt_bind_result (mysqli_stmt $stmt, mixed &$var1, [mixed &$...]) Binds columns in the result set to variables. When mysqli_stmt_fetch(3) is called to fetch data, the MySQL client/server protocol places the data for the bound columns into the speci- fied variables $var1, .... Note Note that all columns must be bound after mysqli_stmt_execute(3) and prior to calling mysqli_stmt_fetch(3). Depending on column types bound variables can silently change to the corresponding PHP type. A column can be bound or rebound at any time, even after a result set has been partially retrieved. The new binding takes effect the next time mysqli_stmt_fetch(3) is called. PARAMETERS
o $ stmt -Procedural style only: A statement identifier returned by mysqli_stmt_init(3). o $var1 - The variable to be bound. RETURN VALUES
Returns TRUE on success or FALSE on failure. EXAMPLES
Example #1 Object oriented style <?php $mysqli = new mysqli("localhost", "my_user", "my_password", "world"); if (mysqli_connect_errno()) { printf("Connect failed: %s ", mysqli_connect_error()); exit(); } /* prepare statement */ if ($stmt = $mysqli->prepare("SELECT Code, Name FROM Country ORDER BY Name LIMIT 5")) { $stmt->execute(); /* bind variables to prepared statement */ $stmt->bind_result($col1, $col2); /* fetch values */ while ($stmt->fetch()) { printf("%s %s ", $col1, $col2); } /* close statement */ $stmt->close(); } /* close connection */ $mysqli->close(); ?> Example #2 Procedural style <?php $link = mysqli_connect("localhost", "my_user", "my_password", "world"); /* check connection */ if (!$link) { printf("Connect failed: %s ", mysqli_connect_error()); exit(); } /* prepare statement */ if ($stmt = mysqli_prepare($link, "SELECT Code, Name FROM Country ORDER BY Name LIMIT 5")) { mysqli_stmt_execute($stmt); /* bind variables to prepared statement */ mysqli_stmt_bind_result($stmt, $col1, $col2); /* fetch values */ while (mysqli_stmt_fetch($stmt)) { printf("%s %s ", $col1, $col2); } /* close statement */ mysqli_stmt_close($stmt); } /* close connection */ mysqli_close($link); ?> The above examples will output: AFG Afghanistan ALB Albania DZA Algeria ASM American Samoa AND Andorra SEE ALSO
mysqli_stmt_get_result(3), mysqli_stmt_bind_param(3), mysqli_stmt_execute(3), mysqli_stmt_fetch(3), mysqli_prepare(3), mysqli_stmt_pre- pare(3), mysqli_stmt_init(3), mysqli_stmt_errno(3), mysqli_stmt_error(3). PHP Documentation Group MYSQLI_STMT_BIND_RESULT(3)
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