exec function not returning all rows

Question

My awk command works as expected and returns 2 lines at command prompt.

When I use php "exec" function, it returns only the second line.

echo exec("awk -v RS=\",\" '/some_text/' test1.html");

How do I return all output of shell command using PHP?

Answer 1

Return Values

The last line from the result of the command. If you need to execute a command and have all the data from the command passed directly back without any interference, use the passthru() function.

Returns false on failure.

To get the output of the executed command, be sure to set and use the output parameter.

It only returns the last line of output so use:

output

If the output argument is present, then the specified array will be filled with every line of output from the command. Trailing whitespace, such as \n, is not included in this array. Note that if the array already contains some elements, exec() will append to the end of the array. If you do not want the function to append elements, call unset() on the array before passing it to exec().

http://php.net/manual/en/function.exec.php

exec("awk -v RS=\",\" '/some_text/' test1.html", $out);
foreach($out as $line) {
    echo $line;
}

Answer 2

Though this question is answered, I'm posting this alternate solution for more options.

This solution replaces line-breaks directly on shell using shell tr command, and pipes through the one-line result.

Also php's exec command requires a second argument for assigning the shell output, while shell_exec can be used directly to declare or output the result of shell execution.

Updating above example, to replace line-breaks \n with a blank space, which could be any other string, however, cannot be empty.

echo shell_exec("awk -v RS=\",\" '/some_text/' test1.html | tr '\n' ' '");

To simply remove all line-breaks without replacements using the -d flag of tr command,

echo shell_exec("awk -v RS=\",\" '/some_text/' test1.html | tr -d '\n'");