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Diffstat (limited to 'starship/src/init/mod.rs')
| -rw-r--r-- | starship/src/init/mod.rs | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/starship/src/init/mod.rs b/starship/src/init/mod.rs new file mode 100644 index 000000000..85f8f80d7 --- /dev/null +++ b/starship/src/init/mod.rs @@ -0,0 +1,170 @@ +use std::ffi::OsStr; +use std::path::Path; +use std::{env, io}; + +/* We use a two-phase init here: the first phase gives a simple command to the +shell. This command evaluates a more complicated script using `source` and +process substitution. + +Directly using `eval` on a shell script causes it to be evaluated in +a single line, which sucks because things like comments will comment out the +rest of the script, and you have to spam semicolons everywhere. By using +source and process substitutions, we make it possible to comment and debug +the init scripts. + +In the future, this may be changed to just directly evaluating the initscript +using whatever mechanism is available in the host shell--this two-phase solution +has been developed as a compatibility measure with `eval $(starship init X)` +*/ + +fn path_to_starship() -> io::Result<String> { + let current_exe = env::current_exe()? + .to_str() + .ok_or_else(|| io::Error::new(io::ErrorKind::Other, "can't convert to str"))? + .to_string(); + Ok(current_exe) +} + +/* This prints the setup stub, the short piece of code which sets up the main +init code. The stub produces the main init script, then evaluates it with +`source` and process substitution */ +pub fn init_stub(shell_name: &str) -> io::Result<()> { + log::debug!("Shell name: {}", shell_name); + + let shell_basename = Path::new(shell_name).file_stem().and_then(OsStr::to_str); + + let starship = path_to_starship()?.replace("\"", "\"'\"'\""); + + let setup_stub = match shell_basename { + Some("bash") => { + /* + * The standard bash bootstrap is: + * `source <(starship init bash --print-full-init)` + * + * Unfortunately there is an issue with bash 3.2 (the MacOS + * default) which prevents this from working. It does not support + * `source` with process substitution. + * + * There are more details here: https://stackoverflow.com/a/32596626 + * + * The workaround for MacOS is to use the `/dev/stdin` trick you + * see below. However, there are some systems with emulated POSIX + * environments which do not support `/dev/stdin`. For example, + * `Git Bash` within `Git for Windows and `Termux` on Android. + * + * Fortunately, these apps ship with recent-ish versions of bash. + * Git Bash is currently shipping bash 4.4 and Termux is shipping + * bash 5.0. + * + * Some testing has suggested that bash 4.0 is also incompatible + * with the standard bootstrap, whereas bash 4.1 appears to be + * consistently compatible. + * + * The upshot of all of this, is that we will use the standard + * bootstrap whenever the bash version is 4.1 or higher. Otherwise, + * we fall back to the `/dev/stdin` solution. + * + * More background can be found in these pull requests: + * https://github.com/starship/starship/pull/241 + * https://github.com/starship/starship/pull/278 + */ + let script = { + format!( + r#"if [ "${{BASH_VERSINFO[0]}}" -gt 4 ] || ([ "${{BASH_VERSINFO[0]}}" -eq 4 ] && [ "${{BASH_VERSINFO[1]}}" -ge 1 ]) +then +source <("{}" init bash --print-full-init) +else +source /dev/stdin <<<"$("{}" init bash --print-full-init)" +fi"#, + starship, starship + ) + }; + + Some(script) + } + Some("zsh") => { + let script = format!("source <(\"{}\" init zsh --print-full-init)", starship); + Some(script) + } + Some("fish") => { + // Fish does process substitution with pipes and psub instead of bash syntax + let script = format!( + "source (\"{}\" init fish --print-full-init | psub)", + starship + ); + Some(script) + } + None => { + println!( + "Invalid shell name provided: {}\\n\ + If this issue persists, please open an \ + issue in the starship repo: \\n\ + https://github.com/starship/starship/issues/new\\n\"", + shell_name + ); + None + } + Some(shell_basename) => { + println!( + "printf \"\\n{0} is not yet supported by starship.\\n\ + For the time being, we support bash, zsh, and fish.\\n\ + Please open an issue in the starship repo if you would like to \ + see support for {0}:\\nhttps://github.com/starship/starship/issues/new\"\\n\\n", + shell_basename + ); + None + } + }; + if let Some(script) = setup_stub { + print!("{}", script); + }; + Ok(()) +} + +/* This function (called when `--print-full-init` is passed to `starship init`) +prints out the main initialization script */ +pub fn init_main(shell_name: &str) -> io::Result<()> { + let starship_path = path_to_starship()?.replace("\"", "\"'\"'\""); + + let setup_script = match shell_name { + "bash" => Some(BASH_INIT), + "zsh" => Some(ZSH_INIT), + "fish" => Some(FISH_INIT), + _ => { + println!( + "printf \"Shell name detection failed on phase two init.\\n\ + This probably indicates a bug within starship: please open\\n\ + an issue at https://github.com/starship/starship/issues/new\\n\"" + ); + None + } + }; + if let Some(script) = setup_script { + // Set up quoting for starship path in case it has spaces. + let starship_path_string = format!("\"{}\"", starship_path); + let script = script.replace("::STARSHIP::", &starship_path_string); + print!("{}", script); + }; + Ok(()) +} + +/* GENERAL INIT SCRIPT NOTES + +Each init script will be passed as-is. Global notes for init scripts are in this +comment, with additional per-script comments in the strings themselves. + +JOBS: The argument to `--jobs` is quoted because MacOS's `wc` leaves whitespace +in the output. We pass it to starship and do the whitespace removal in Rust, +to avoid the cost of an additional shell fork every shell draw. + +Note that the init scripts are not in their final form--they are processed by +`starship init` prior to emitting the final form. In this processing, some tokens +are replaced, e.g. `::STARSHIP::` is replaced by the full path to the +starship binary. +*/ + +const BASH_INIT: &str = include_str!("starship.bash"); + +const ZSH_INIT: &str = include_str!("starship.zsh"); + +const FISH_INIT: &str = include_str!("starship.fish"); |