implement dry-run and add tests

.gitignore

@@ -0,0 +1,4 @@
+gargs_race
+binaries
+ssshtest
+gargs

.travis.yml

@@ -0,0 +1,14 @@
+language: go
+
+os:
+  - linux
+  - osx
+
+go:
+  - 1.4
+  - 1.5
+  - 1.6
+
+script:
+    - ./tests/functional-test.sh
+

README.md

@@ -62,7 +62,7 @@ Usage
 =====
 
 ```
-usage: gargs [--procs PROCS] [--nlines NLINES] [--sep SEP] [--shell SHELL] [--verbose] [--continueonerror] [--ordered] COMMAND
+usage: gargs [--procs PROCS] [--nlines NLINES] [--sep SEP] [--shell SHELL] [--verbose] [--continue-on-error] [--ordered] [--dry-run] COMMAND
 
 positional arguments:
   command                command to execute
@@ -75,9 +75,10 @@ options:
   --sep SEP, -s SEP      regular expression split line with to fill multiple template spots default is not to split. -s and -n are mutually exclusive.
   --shell SHELL          shell to use [default: bash]
   --verbose, -v          print commands to stderr before they are executed.
-  --continueonerror, -c
+  --continue-on-error, -c
                          report errors but don't stop the entire execution (which is the default).
   --ordered, -o          keep output in order of input; default is to output in order of return which greatly improves parallelization.
+  --dry-run, -d          print (but do not run) the commands (for debugging)
   --help, -h             display this help and exit
 ```
 

main.go

@@ -18,7 +18,7 @@ import (
 	"github.com/brentp/xopen"
 )
 
-const VERSION = "0.2.0"
+const VERSION = "0.3.0"
 
 type Args struct {
 	Procs           int    `arg:"-p,help:number of processes to use"`
@@ -27,8 +27,9 @@ type Args struct {
 	Sep             string `arg:"-s,help:regular expression split line with to fill multiple template spots default is not to split. -s and -n are mutually exclusive."`
 	Shell           string `arg:"help:shell to use"`
 	Verbose         bool   `arg:"-v,help:print commands to stderr before they are executed."`
-	ContinueOnError bool   `arg:"-c,help:report errors but don't stop the entire execution (which is the default)."`
+	ContinueOnError bool   `arg:"-c,--continue-on-error,help:report errors but don't stop the entire execution (which is the default)."`
 	Ordered         bool   `arg:"-o,help:keep output in order of input; default is to output in order of return which greatly improves parallelization."`
+	DryRun          bool   `arg:"-d,--dry-run,help:print (but do not run) the commands"`
 }
 
 // hold the arguments for each call.
@@ -47,6 +48,7 @@ func main() {
 	args.Verbose = false
 	args.ContinueOnError = false
 	args.Ordered = false
+	args.DryRun = false
 	p := arg.MustParse(&args)
 	if args.Sep != "" && args.Nlines > 1 {
 		p.Fail("must specify either sep (-s) or n-lines (-n), not both")
@@ -190,6 +192,10 @@ func process(ch chan []byte, cmdStr string, args Args, xarg *xargs) {
 	if args.Verbose {
 		fmt.Fprintf(os.Stderr, "command: %s\n", cmdStr)
 	}
+	if args.DryRun {
+		fmt.Fprintf(os.Stdout, "%s\n", cmdStr)
+		return
+	}
 
 	cmd := exec.Command(args.Shell, "-c", cmdStr)
 	cmd.Stderr = os.Stderr

tests/functional-test.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+test -e ssshtest || wget -q https://raw.githubusercontent.com/ryanlayer/ssshtest/master/ssshtest
+
+. ssshtest
+
+go build -o gargs_race -race -a
+
+fn_check_basic() {
+	seq 12 -1 1 | ./gargs_race -p 5 -n 3 -d  -v 'sleep {0}; echo {1} {2}'
+}
+run check_basic fn_check_basic
+assert_exit_code 0
+assert_in_stderr 'command:'
+assert_equal 4 $(wc -l $STDOUT_FILE)
+assert_equal 4 $(grep -c sleep $STDOUT_FILE)
+
+fn_check_sep() {
+	cat tests/t.txt | ./gargs_race --sep "\s+" -p 2 "echo -e '{0}:{1}-{2}' full-line: \'{}\'"
+}
+run check_sep fn_check_sep
+assert_exit_code 0
+assert_in_stdout "chr2:22-33 full-line: 'chr2 22 33'"
+assert_in_stdout "chr1:22-33 full-line: 'chr1 22 33'"
+assert_in_stdout "chr3:22-33 full-line: 'chr3 22 33'"
+assert_in_stdout "chr4:22-33 full-line: 'chr4 22 33'"
+
+

tests/t.txt

@@ -0,0 +1,4 @@
+chr1	22 33
+chr2 22 33
+chr3 22	33
+chr4	22	33