Handle shell built-in commands #47
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Signed-off-by: Itai-Nelken <[email protected]>
Signed-off-by: Itai-Nelken <[email protected]>
| int easter_egg() { | ||
| printf("You found the DollarSkip easter egg!\n"); | ||
| return 0; | ||
| } |
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Nevermind, I skipped past this part, i think this is pretty pointless, fun but pointless and dollarskip is made to merely pass the commands through, not be an actual application.
It should be a possibility that we remove this.
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I'm fine with removing it. I added it just as an example of how to override shell commands that are important enough to implement ourselves.
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We could also rename it to dollarskip and make it print about and version info. If that's what we do, I'll remove the overriding shell commands as we can check for arguments in main(). That will also improve speed as we remove one loop.
A faster way to do this would be with a hash table (map in go), but I didn't want to add my implementation (that is pretty big and not so readable).
Co-authored-by: CleanMachine1 <[email protected]>
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Something I forgot to mention: this slows down dollarskip by about 0.030 seconds. |
Thats an extremely long time. I'm sure the average person will notice 😄 There is no issue. |
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I made a version of the changes here (excluding the "wrapping" of commands) for DollarSkip-go. package main
import (
"fmt" // for printing errors
"os" // for capturing argv
"os/exec" // for running the commands
"strings" // for unslicing the array
)
var unhandled_commands = map[string]bool{
"cd": true,
"alias" : true,
"unalias" : true,
"pushd" : true,
"popd" : true,
"dirs" : true,
"read" : true,
"set" : true,
"readonly" : true,
"unset" : true,
"typeset" : true,
"declare" : true,
"disown" : true,
"enable" : true,
"export" : true,
"exit" : true, // doesn't do anything when run through DollarSkip
"fc" : true,
"history" : true,
"fg" : true,
"getopts" : true,
"hash" : true, // we don't want it to report fake data for the current shell (true for the shell in which it is run)
"jobs" : true, // same reason as the one for 'hash'
"times" : true, // same as above
"local" : true,
}
func main() {
if len(os.Args) < 2 {
os.Exit(1)
}
if _, ok := unhandled_commands[os.Args[1]]; ok {
fmt.Fprintf(os.Stderr, "\x1b[31;1m[DollarSkip: error]: '\x1b[97m%s\x1b[0;1;31m': built-in shell commands aren't supported!\x1b[0m\n", os.Args[1])
os.Exit(1)
}
args := os.Args[1:] // collects given arguments and 1: removes the binary name
unsliced_string := strings.Join(args, " ") // convert to string rather than type []string from args
shell := os.Getenv("SHELL") // Using the env, save the shell
cmd := exec.Command(shell, `-c`, unsliced_string) // Define the command to be run
cmd.Stderr = os.Stderr
cmd.Stdout = os.Stdout
cmd.Stdin = os.Stdin
err := cmd.Run() // Run the command
if exitErr, ok := err.(*exec.ExitError); ok {
exitCode := exitErr.ExitCode()
os.Exit(exitCode)
} else if err != nil {
exitCode := 1
os.Exit(exitCode)
}
} |
This handles built-in shell commands.
this is done by using 2 arrays:
unhandled_shell_builtins: A string array containing the names of built-in commands that don't work through DollarSkip (cdfor example).handled_shell_builtins: An array forWrapper(struct wrapper) that holds commands we wrapped so they work through DollarSkip.To show how the handled shell built-ins work I added an "easter egg" command (
e_egg). I thought about doingpwd, but I don't want to rewrite the bash version.Closes #46
Signed-off-by: Itai-Nelken [email protected]