add support for persistent config

Cargo.toml

@@ -35,14 +35,12 @@ members = [ "grep", "globset", "ignore", "termcolor", "wincolor" ]
 [dependencies]
 atty = "0.2.2"
 bytecount = "0.3.1"
-clap = "2.26"
 encoding_rs = "0.7"
-env_logger = { version = "0.4", default-features = false }
 grep = { version = "0.1.7", path = "grep" }
 ignore = { version = "0.3.1", path = "ignore" }
 lazy_static = "1"
 libc = "0.2"
-log = "0.3"
+log = "0.4"
 memchr = "2"
 memmap = "0.6"
 num_cpus = "1"
@@ -51,14 +49,23 @@ same-file = "1"
 termcolor = { version = "0.3.3", path = "termcolor" }
 globset = { version = "0.2.1", path = "globset" }
 
+[dependencies.clap]
+version = "2.26"
+default-features = false
+features = ["suggestions", "color"]
+
 [target.'cfg(windows)'.dependencies.winapi]
 version = "0.3"
 features = ["std", "winnt"]
 
 [build-dependencies]
-clap = "2.26"
 lazy_static = "1"
 
+[build-dependencies.clap]
+version = "2.26"
+default-features = false
+features = ["suggestions", "color"]
+
 [features]
 avx-accel = ["bytecount/avx-accel"]
 simd-accel = [

README.md

@@ -362,6 +362,50 @@ extensions.
 The syntax supported is
 [documented as part of Rust's regex library](https://doc.rust-lang.org/regex/regex/index.html#syntax).
 
+### Configuration files
+
+ripgrep supports reading configuration files that change ripgrep's default
+behavior. The format of the configuration file is an "rc" style and is very
+simple. It is defined by two rules:
+
+1. Every line is a shell argument, after trimming ASCII whitespace.
+2. Lines starting with '#' (optionally preceded by any amount of
+   ASCII whitespace) are ignored.
+
+ripgrep will look for a single configuration file if and only if the
+`RIPGREP_CONFIG_PATH` environment variable is set and is non-empty. ripgrep
+will parse shell arguments from this file on startup and will behave as if
+the arguments in this file were prepended to any explicit arguments given to
+ripgrep on the command line.
+
+For example, if your ripgreprc file contained a single line:
+
+    --smart-case
+
+then the following command
+
+    RIPGREP_CONFIG_PATH=wherever/.ripgreprc rg foo
+
+would behave identically to the following command
+
+    rg --smart-case foo
+
+ripgrep also provides a flag, --no-config, that when present will suppress
+any and all support for configuration. This includes any future support for
+auto-loading configuration files from pre-determined paths.
+
+Conflicts between configuration files and explicit arguments are handled
+exactly like conflicts in the same command line invocation. That is, this
+command:
+
+    RIPGREP_CONFIG_PATH=wherever/.ripgreprc rg foo --case-sensitive
+
+is exactly equivalent to
+
+    rg --smart-case foo --case-sensitive
+
+in which case, the --case-sensitive flag would override the --smart-case flag.
+
 ### Shell completions
 
 Shell completion files are included in the release tarball for Bash, Fish, Zsh

build.rs

@@ -5,6 +5,7 @@ extern crate lazy_static;
 
 use std::env;
 use std::fs;
+use std::process;
 
 use clap::Shell;
 
@@ -13,14 +14,34 @@ use clap::Shell;
 mod app;
 
 fn main() {
+    // OUT_DIR is set by Cargo and it's where any additional build artifacts
+    // are written.
     let outdir = match env::var_os("OUT_DIR") {
-        None => return,
         Some(outdir) => outdir,
+        None => {
+            eprintln!(
+                "OUT_DIR environment variable not defined. \
+                 Please file a bug: \
+                 https://github.com/BurntSushi/ripgrep/issues/new");
+            process::exit(1);
+        }
     };
     fs::create_dir_all(&outdir).unwrap();
 
+    // Use clap to build completion files.
     let mut app = app::app();
     app.gen_completions("rg", Shell::Bash, &outdir);
     app.gen_completions("rg", Shell::Fish, &outdir);
     app.gen_completions("rg", Shell::PowerShell, &outdir);
+    // Note that we do not use clap's support for zsh. Instead, zsh completions
+    // are manually maintained in `complete/_rg`.
+
+    // Make the current git hash available to the build.
+    let result = process::Command::new("git")
+        .args(&["rev-parse", "--short=10", "HEAD"])
+        .output();
+    if let Ok(output) = result {
+        let hash = String::from_utf8_lossy(&output.stdout);
+        println!("cargo:rustc-env=RIPGREP_BUILD_GIT_HASH={}", hash);
+    }
 }

complete/_rg

@@ -54,6 +54,7 @@ _rg() {
     '(--mmap --no-mmap)--mmap[search using memory maps when possible]'
     '(-H --with-filename --no-filename)--no-filename[suppress all file names]'
     "(-p --heading --pretty --vimgrep)--no-heading[don't group matches by file name]"
+    "--no-config[don't load configuration files]"
     "(--no-ignore-parent)--no-ignore[don't respect ignore files]"
     "--no-ignore-parent[don't respect ignore files in parent directories]"
     "--no-ignore-vcs[don't respect version control ignore files]"

doc/rg.1

@@ -403,6 +403,17 @@ context related options.)
 .RS
 .RE
 .TP
+.B \-\-no\-config
+Never read configuration files.
+When this flag is present, ripgrep will not respect the
+RIPGREP_CONFIG_PATH environment variable.
+.RS
+.PP
+If ripgrep ever grows a feature to automatically read configuration
+files in pre\-defined locations, then this flag will also disable that
+behavior as well.
+.RE
+.TP
 .B \-\-no\-messages
 Suppress all error messages.
 .RS
@@ -597,6 +608,77 @@ ripgrep.
 Note that this must be passed to every invocation of rg.
 .RS
 .RE
+.SH CONFIGURATION FILES
+.PP
+ripgrep supports reading configuration files that change ripgrep\[aq]s
+default behavior.
+The format of the configuration file is an "rc" style and is very
+simple.
+It is defined by two rules:
+.IP
+.nf
+\f[C]
+1.\ Every\ line\ is\ a\ shell\ argument,\ after\ trimming\ ASCII\ whitespace.
+2.\ Lines\ starting\ with\ \[aq]#\[aq]\ (optionally\ preceded\ by\ any\ amount\ of
+\ \ \ ASCII\ whitespace)\ are\ ignored.
+\f[]
+.fi
+.PP
+ripgrep will look for a single configuration file if and only if the
+RIPGREP_CONFIG_PATH environment variable is set and is non\-empty.
+ripgrep will parse shell arguments from this file on startup and will
+behave as if the arguments in this file were prepended to any explicit
+arguments given to ripgrep on the command line.
+.PP
+For example, if your ripgreprc file contained a single line:
+.IP
+.nf
+\f[C]
+\-\-smart\-case
+\f[]
+.fi
+.PP
+then the following command
+.IP
+.nf
+\f[C]
+RIPGREP_CONFIG_PATH=wherever/.ripgreprc\ rg\ foo
+\f[]
+.fi
+.PP
+would behave identically to the following command
+.IP
+.nf
+\f[C]
+rg\ \-\-smart\-case\ foo
+\f[]
+.fi
+.PP
+ripgrep also provides a flag, \-\-no\-config, that when present will
+suppress any and all support for configuration.
+This includes any future support for auto\-loading configuration files
+from pre\-determined paths.
+.PP
+Conflicts between configuration files and explicit arguments are handled
+exactly like conflicts in the same command line invocation.
+That is, this command:
+.IP
+.nf
+\f[C]
+RIPGREP_CONFIG_PATH=wherever/.ripgreprc\ rg\ foo\ \-\-case\-sensitive
+\f[]
+.fi
+.PP
+is exactly equivalent to
+.IP
+.nf
+\f[C]
+rg\ \-\-smart\-case\ foo\ \-\-case\-sensitive
+\f[]
+.fi
+.PP
+in which case, the \-\-case\-sensitive flag would override the
+\-\-smart\-case flag.
 .SH SHELL COMPLETION
 .PP
 Shell completion files are included in the release tarball for Bash,