Using Escape Codes and Setting Window Title on PS1 for ksh (Korn Shell)

I set up the following in my ~/.profile for my ksh login:

export HOST=$(hostname)

export PS1=$(perl -e 'printf "33]0;${USER}@${HOST}:${PWD}07$"')

Unfortunately, ksh doesn’t understand escape codes, so perl or awk is necessary to pull this off–or you can enter them literally via your editor. I like the perl route just for ease of maintenance.

This was inspired by: Setting window title via escape sequences. Of course, the bash version is *much* simpler:

export PS1="e]2;${USER}@${HOSTNAME}: ${PWD}a"

Other links of interest:

Date formatting for Single Unix Specification(R) versions of “date”

The date command is wonderful for formatting dates, as such

date --date="2010-01-01" +%Y%j

But what happens when you’re on a system whose date command only supports the -u [UTC] and + [for formatting] options?

Below is a quick hack in straight C that provides the ability to format a date that you provide. This is ideal if your unix install of perl is very basic or non-existent, but you still have access to the C compiler.

Compiling the target would go as follows:

gcc strptime.c -o strptime

Running the output would be as follows:

./strptime "2010-01-01" "%Y%j"

strptime.c source code–Please note: there is limited error checking for the wrong arguments, etc., and overlapping a built-in name such as strptime() isn’t the best of practices…


int main(int argc, char *argv[]) {
    struct tm tm;
    time_t t;
    char string[255];

    if(strptime(argv[1], "%Y-%m-%d", &tm) == NULL) {
        if (strptime(argv[1], "%m/%d/%Y", &tm) == NULL ) {
            fprintf(stderr, "format errorn");
            return 1;
    strftime(string, sizeof(string) - 1, argv[2], &tm);
    return 0;

Perl Documentation Bookmarklets

Below are some bookmarklets to quick link to CPAN documentation… Click and drag the links to your bookmark bar or use the included source code to create the bookmarklets.

They will generate a prompt something like this when clicked:

Bookmarklet to search for a keyword in CPAN documentation: Search CPAN



Bookmarklet to bring up specific module page [case-sensitive, e.g., GetOpt::Long]: CPAN Page



Inspired by

Formatting a Julian Date [Julian Day / Day of Year] in Unix

This is one of those commands that’s so simple once you recall it that you’ll smack yourself for not knowing it.

If you’re ever in doubt, man date.

# displays the 2-digit year + day of the year, Jan 14, 2011 = "11014"
date +%y%j

# sets filename to MyFilename + 2-digit year + day of the year
# Jan 14, 2011 = MyFilename11014
filename=MyFilename`date +%y%j`

Remember to use lowercase ‘y’. Uppercase ‘Y’ will give you a 4-digit year.