/tmp>cat error.c
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>

int main(int argc, char ** argv)
{
        int fd;
        char buf[100];
        ssize_t n;

        fd = open("foo", O_RDONLY);
        if (fd == -1) {
                perror("failed to open foo"); /* evaluates errno */
                return 1;
        }

        n = read(fd, buf, sizeof(buf));
        if (n == -1) {
                perror("failed to read from foo");
                return 2;
        }
        if (n != sizeof(buf)) {
                fprintf(stderr, "Short read from foo (got %z, expected %z)\n", n, sizeof(buf));
                return 3;
        }

        if (close(fd) == -1) {
                perror("failed to close foo");
                return 4;
        }

        // and so on ...
}

/tmp>make error
cc     error.c   -o error

/tmp>./error
failed to open foo: No such file or directory

/tmp>

##</code><code>##

try {
    line = console.readLine();

    if (line.length() == 0) {
        throw new EmptyLineException("The line read from console was empty!");
    }

    console.printLine("Hello %s!" % line);
}
catch (EmptyLineException e) {
    console.printLine("Hello!");
}
catch (Exception e) {
    console.printLine("Error: " + e.message());
}
else {
    console.printLine("The program ran successfully.");
}
finally {
    console.printLine("The program is now terminating.");
}

##</code><code>##

use Try::Tiny;
$dbh->{AutoCommit} = 0;  # enable transactions, if possible
$dbh->{RaiseError} = 1;
try {
    foo(...)        # do lots of work here
    bar(...)        # including inserts
    baz(...)        # and updates
    $dbh->commit;   # commit the changes if we get this far
} catch {
    warn "Transaction aborted because $_"; # Try::Tiny copies $@ into $_
    # now rollback to undo the incomplete changes
    # but do it in an eval{} as it may also fail
    eval { $dbh->rollback };
    # add other application on-error-clean-up code here
};

##</code><code>##

$h->method(@args) or die $h->errstr;