Questions and Answers

Absent Features

How do I color output?

Para leaves coloring output to other tools (e.g., Colout, the Generic Colouriser, or Supercat).

However, if a program’s output is prefixed with its name, as required by style(9) and the GNU coding standards (chap. 4.4), then the output can be colored with tput(1) and sed(1).

Generate the ANSI escape codes for your favorite colors with tput:

blue="$(tput setaf 4)"
cyan="$(tput setaf 6)"
reset="$(tput sgr0)"

Tip

See terminfo(5) for how numbers map to colors.

Then pipe para’s output through a sed-script that applies them:

para 'echo foo: qux' 'echo bar: quux' |
sed "
    s/\(^foo:\)\(.*\)/$blue\1$reset\2/;
    s/\(^bar:\)\(.*\)/$cyan\1$reset\2/;
"

Troubleshooting

-l: getloadavg(3) not available

The load average is queried with getloadavg(3). However, getloadavg() is not supported by the system or not declared in stdlib.h, or Para has been compiled to only use interfaces standardized by POSIX.1-2008 (getloadavg() is non-standard).

You can try to recompile para with:

./configure CPPFLAGS=
make

Environment full or Too many variables

By default, Para permits only 255 variables in a job’s environment. You can raise that limit by re-compiling Para with MAX_NVARS set to a higher value. For example,

./configure -DMAX_NVARS=2048
make

configures Para to permit up to 2047 environment variables (one slot is needed for a terminator).

para.c:line: error

Error messages that mention para.c indicate bugs. Please be so kind and report them.

wordsplit: Invalid argument or -k: Invalid argument

Arguments are invalid if they cannot be split into words. This happens when they contain unbalanced quotes or end with an escape (\).