refactor (shell) : Refactor CRC unix/linux shell detection logic using gopsutil (#4562)

go.mod

@@ -44,7 +44,7 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/r3labs/sse/v2 v2.10.0
 	github.com/segmentio/analytics-go/v3 v3.3.0
-	github.com/shirou/gopsutil/v3 v3.24.5
+	github.com/shirou/gopsutil/v4 v4.24.12
 	github.com/sirupsen/logrus v1.9.3
 	github.com/spf13/cast v1.7.1
 	github.com/spf13/cobra v1.8.1
@@ -92,6 +92,7 @@ require (
 	github.com/docker/docker v27.1.1+incompatible // indirect
 	github.com/docker/docker-credential-helpers v0.8.2 // indirect
 	github.com/docker/go-connections v0.5.0 // indirect
+	github.com/ebitengine/purego v0.8.2 // indirect
 	github.com/emicklei/go-restful/v3 v3.11.0 // indirect
 	github.com/fatih/color v1.18.0 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
@@ -136,7 +137,7 @@ require (
 	github.com/klauspost/pgzip v1.2.6 // indirect
 	github.com/letsencrypt/boulder v0.0.0-20240418210053-89b07f4543e0 // indirect
 	github.com/linuxkit/virtsock v0.0.0-20220523201153-1a23e78aa7a2 // indirect
-	github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 // indirect
+	github.com/lufia/plan9stats v0.0.0-20240909124753-873cd0166683 // indirect
 	github.com/magiconair/properties v1.8.7 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
@@ -159,7 +160,7 @@ require (
 	github.com/pelletier/go-toml/v2 v2.2.2 // indirect
 	github.com/pierrec/lz4/v4 v4.1.14 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
-	github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c // indirect
+	github.com/power-devops/perfstat v0.0.0-20240221224432-82ca36839d55 // indirect
 	github.com/proglottis/gpgme v0.1.3 // indirect
 	github.com/qdm12/dns/v2 v2.0.0-rc6 // indirect
 	github.com/qdm12/gosettings v0.4.1 // indirect
@@ -168,7 +169,6 @@ require (
 	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
 	github.com/secure-systems-lab/go-securesystemslib v0.8.0 // indirect
 	github.com/segmentio/backo-go v1.0.1 // indirect
-	github.com/shoenig/go-m1cpu v0.1.6 // indirect
 	github.com/sigstore/fulcio v1.4.5 // indirect
 	github.com/sigstore/rekor v1.3.6 // indirect
 	github.com/sigstore/sigstore v1.8.4 // indirect
@@ -179,8 +179,8 @@ require (
 	github.com/subosito/gotenv v1.6.0 // indirect
 	github.com/syndtr/gocapability v0.0.0-20200815063812-42c35b437635 // indirect
 	github.com/titanous/rocacheck v0.0.0-20171023193734-afe73141d399 // indirect
-	github.com/tklauser/go-sysconf v0.3.12 // indirect
-	github.com/tklauser/numcpus v0.6.1 // indirect
+	github.com/tklauser/go-sysconf v0.3.14 // indirect
+	github.com/tklauser/numcpus v0.9.0 // indirect
 	github.com/u-root/uio v0.0.0-20240224005618-d2acac8f3701 // indirect
 	github.com/ulikunitz/xz v0.5.12 // indirect
 	github.com/vbatts/tar-split v0.11.5 // indirect

go.sum

@@ -105,6 +105,8 @@ github.com/docker/go-units v0.5.0 h1:69rxXcBk27SvSaaxTtLh/8llcHD8vYHT7WSdRZ/jvr4
 github.com/docker/go-units v0.5.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
 github.com/elazarl/goproxy v1.7.0 h1:EXv2nV4EjM60ZtsEVLYJG4oBXhDGutMKperpHsZ/v+0=
 github.com/elazarl/goproxy v1.7.0/go.mod h1:X/5W/t+gzDyLfHW4DrMdpjqYjpXsURlBt9lpBDxZZZQ=
+github.com/ebitengine/purego v0.8.2 h1:jPPGWs2sZ1UgOSgD2bClL0MJIqu58nOmIcBuXr62z1I=
+github.com/ebitengine/purego v0.8.2/go.mod h1:iIjxzd6CiRiOG0UyXP+V1+jWqUXVjPKLAI0mRfJZTmQ=
 github.com/emicklei/go-restful/v3 v3.11.0 h1:rAQeMHw1c7zTmncogyy8VvRZwtkmkZ4FxERmMY4rD+g=
 github.com/emicklei/go-restful/v3 v3.11.0/go.mod h1:6n3XBCmQQb25CM2LCACGz8ukIrRry+4bhvbpWn3mrbc=
 github.com/fatih/color v1.18.0 h1:S8gINlzdQ840/4pfAwic/ZE0djQEH3wM94VfqLTZcOM=
@@ -162,7 +164,6 @@ github.com/google/btree v1.1.2 h1:xf4v41cLI2Z6FxbKm+8Bu+m8ifhj15JuZ9sa0jZCMUU=
 github.com/google/btree v1.1.2/go.mod h1:qOPhT0dTNdNzV6Z/lhRX0YXUafgPLFUh+gZMl761Gm4=
 github.com/google/gnostic-models v0.6.8 h1:yo/ABAfM5IMRsS1VnXjTBvUb61tFIHozhlYvRgGre9I=
 github.com/google/gnostic-models v0.6.8/go.mod h1:5n7qKqH0f5wFt+aWF8CW6pZLLNOfYuF5OpfBSENuI8U=
-github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
@@ -244,8 +245,8 @@ github.com/letsencrypt/boulder v0.0.0-20240418210053-89b07f4543e0 h1:aiPrFdHDCCv
 github.com/letsencrypt/boulder v0.0.0-20240418210053-89b07f4543e0/go.mod h1:srVwm2N3DC/tWqQ+igZXDrmKlNRN8X/dmJ1wEZrv760=
 github.com/linuxkit/virtsock v0.0.0-20220523201153-1a23e78aa7a2 h1:DZMFueDbfz6PNc1GwDRA8+6lBx1TB9UnxDQliCqR73Y=
 github.com/linuxkit/virtsock v0.0.0-20220523201153-1a23e78aa7a2/go.mod h1:SWzULI85WerrFt3u+nIm5F9l7EvxZTKQvd0InF3nmgM=
-github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 h1:6E+4a0GO5zZEnZ81pIr0yLvtUWk2if982qA3F3QD6H4=
-github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0/go.mod h1:zJYVVT2jmtg6P3p1VtQj7WsuWi/y4VnjVBn7F8KPB3I=
+github.com/lufia/plan9stats v0.0.0-20240909124753-873cd0166683 h1:7UMa6KCCMjZEMDtTVdcGu0B1GmmC7QJKiCCjyTAWQy0=
+github.com/lufia/plan9stats v0.0.0-20240909124753-873cd0166683/go.mod h1:ilwx/Dta8jXAgpFYFvSWEMwxmbWXyiUHkd5FwyKhb5k=
 github.com/magiconair/properties v1.8.7 h1:IeQXZAiQcpL9mgcAe1Nu6cX9LLw6ExEHKjN0VQdvPDY=
 github.com/magiconair/properties v1.8.7/go.mod h1:Dhd985XPs7jluiymwWYZ0G4Z61jb3vdS329zhj2hYo0=
 github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=
@@ -326,8 +327,8 @@ github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c h1:ncq/mPwQF4JjgDlrVEn3C11VoGHZN7m8qihwgMEtzYw=
-github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c/go.mod h1:OmDBASR4679mdNQnz2pUhc2G8CO2JrUAVFDRBDP/hJE=
+github.com/power-devops/perfstat v0.0.0-20240221224432-82ca36839d55 h1:o4JXh1EVt9k/+g42oCprj/FisM4qX9L3sZB3upGN2ZU=
+github.com/power-devops/perfstat v0.0.0-20240221224432-82ca36839d55/go.mod h1:OmDBASR4679mdNQnz2pUhc2G8CO2JrUAVFDRBDP/hJE=
 github.com/proglottis/gpgme v0.1.3 h1:Crxx0oz4LKB3QXc5Ea0J19K/3ICfy3ftr5exgUK1AU0=
 github.com/proglottis/gpgme v0.1.3/go.mod h1:fPbW/EZ0LvwQtH8Hy7eixhp1eF3G39dtx7GUN+0Gmy0=
 github.com/prometheus/client_golang v1.19.0 h1:ygXvpU1AoN1MhdzckN+PyD9QJOSD4x7kmXYlnfbA6JU=
@@ -360,12 +361,8 @@ github.com/segmentio/analytics-go/v3 v3.3.0 h1:8VOMaVGBW03pdBrj1CMFfY9o/rnjJC+1w
 github.com/segmentio/analytics-go/v3 v3.3.0/go.mod h1:p8owAF8X+5o27jmvUognuXxdtqvSGtD0ZrfY2kcS9bE=
 github.com/segmentio/backo-go v1.0.1 h1:68RQccglxZeyURy93ASB/2kc9QudzgIDexJ927N++y4=
 github.com/segmentio/backo-go v1.0.1/go.mod h1:9/Rh6yILuLysoQnZ2oNooD2g7aBnvM7r/fNVxRNWfBc=
-github.com/shirou/gopsutil/v3 v3.24.5 h1:i0t8kL+kQTvpAYToeuiVk3TgDeKOFioZO3Ztz/iZ9pI=
-github.com/shirou/gopsutil/v3 v3.24.5/go.mod h1:bsoOS1aStSs9ErQ1WWfxllSeS1K5D+U30r2NfcubMVk=
-github.com/shoenig/go-m1cpu v0.1.6 h1:nxdKQNcEB6vzgA2E2bvzKIYRuNj7XNJ4S/aRSwKzFtM=
-github.com/shoenig/go-m1cpu v0.1.6/go.mod h1:1JJMcUBvfNwpq05QDQVAnx3gUHr9IYF7GNg9SUEw2VQ=
-github.com/shoenig/test v0.6.4 h1:kVTaSd7WLz5WZ2IaoM0RSzRsUD+m8wRR+5qvntpn4LU=
-github.com/shoenig/test v0.6.4/go.mod h1:byHiCGXqrVaflBLAMq/srcZIHynQPQgeyvkvXnjqq0k=
+github.com/shirou/gopsutil/v4 v4.24.12 h1:qvePBOk20e0IKA1QXrIIU+jmk+zEiYVVx06WjBRlZo4=
+github.com/shirou/gopsutil/v4 v4.24.12/go.mod h1:DCtMPAad2XceTeIAbGyVfycbYQNBGk2P8cvDi7/VN9o=
 github.com/sigstore/fulcio v1.4.5 h1:WWNnrOknD0DbruuZWCbN+86WRROpEl3Xts+WT2Ek1yc=
 github.com/sigstore/fulcio v1.4.5/go.mod h1:oz3Qwlma8dWcSS/IENR/6SjbW4ipN0cxpRVfgdsjMU8=
 github.com/sigstore/rekor v1.3.6 h1:QvpMMJVWAp69a3CHzdrLelqEqpTM3ByQRt5B5Kspbi8=
@@ -416,10 +413,10 @@ github.com/syndtr/gocapability v0.0.0-20200815063812-42c35b437635 h1:kdXcSzyDtse
 github.com/syndtr/gocapability v0.0.0-20200815063812-42c35b437635/go.mod h1:hkRG7XYTFWNJGYcbNJQlaLq0fg1yr4J4t/NcTQtrfww=
 github.com/titanous/rocacheck v0.0.0-20171023193734-afe73141d399 h1:e/5i7d4oYZ+C1wj2THlRK+oAhjeS/TRQwMfkIuet3w0=
 github.com/titanous/rocacheck v0.0.0-20171023193734-afe73141d399/go.mod h1:LdwHTNJT99C5fTAzDz0ud328OgXz+gierycbcIx2fRs=
-github.com/tklauser/go-sysconf v0.3.12 h1:0QaGUFOdQaIVdPgfITYzaTegZvdCjmYO52cSFAEVmqU=
-github.com/tklauser/go-sysconf v0.3.12/go.mod h1:Ho14jnntGE1fpdOqQEEaiKRpvIavV0hSfmBq8nJbHYI=
-github.com/tklauser/numcpus v0.6.1 h1:ng9scYS7az0Bk4OZLvrNXNSAO2Pxr1XXRAPyjhIx+Fk=
-github.com/tklauser/numcpus v0.6.1/go.mod h1:1XfjsgE2zo8GVw7POkMbHENHzVg3GzmoZ9fESEdAacY=
+github.com/tklauser/go-sysconf v0.3.14 h1:g5vzr9iPFFz24v2KZXs/pvpvh8/V9Fw6vQK5ZZb78yU=
+github.com/tklauser/go-sysconf v0.3.14/go.mod h1:1ym4lWMLUOhuBOPGtRcJm7tEGX4SCYNEEEtghGG/8uY=
+github.com/tklauser/numcpus v0.9.0 h1:lmyCHtANi8aRUgkckBgoDk1nHCux3n2cgkJLXdQGPDo=
+github.com/tklauser/numcpus v0.9.0/go.mod h1:SN6Nq1O3VychhC1npsWostA+oW+VOQTxZrS604NSRyI=
 github.com/u-root/uio v0.0.0-20240224005618-d2acac8f3701 h1:pyC9PaHYZFgEKFdlp3G8RaCKgVpHZnecvArXvPXcFkM=
 github.com/u-root/uio v0.0.0-20240224005618-d2acac8f3701/go.mod h1:P3a5rG4X7tI17Nn3aOIAYr5HbIMukwXG0urG0WuL8OA=
 github.com/ulikunitz/xz v0.5.12 h1:37Nm15o69RwBkXM0J6A5OlE67RZTfzUxTj8fB3dfcsc=
@@ -495,8 +492,6 @@ golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
 golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=

pkg/crc/preflight/preflight_checks_nonlinux.go

@@ -15,7 +15,7 @@ import (
 	"github.com/crc-org/crc/v2/pkg/crc/daemonclient"
 	crcerrors "github.com/crc-org/crc/v2/pkg/crc/errors"
 	"github.com/crc-org/crc/v2/pkg/crc/logging"
-	"github.com/shirou/gopsutil/v3/process"
+	"github.com/shirou/gopsutil/v4/process"
 )
 
 func killDaemonProcess() error {

pkg/drivers/vfkit/driver_darwin.go

@@ -34,7 +34,7 @@ import (
 	"github.com/crc-org/machine/libmachine/state"
 	"github.com/crc-org/vfkit/pkg/config"
 	"github.com/pkg/errors"
-	"github.com/shirou/gopsutil/v3/process"
+	"github.com/shirou/gopsutil/v4/process"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/sys/unix"
 )

pkg/os/shell/shell.go

@@ -3,11 +3,8 @@ package shell
 import (
 	"fmt"
 	"os"
-	"sort"
-	"strconv"
 	"strings"
 
-	"github.com/crc-org/crc/v2/pkg/crc/logging"
 	crcos "github.com/crc-org/crc/v2/pkg/os"
 )
 
@@ -154,83 +151,3 @@ func IsWindowsSubsystemLinux() bool {
 	}
 	return false
 }
-
-// detectShellByInvokingCommand is a utility method that tries to detect current shell in use by invoking `ps` command.
-// This method is extracted so that it could be used by unix systems as well as Windows (in case of WSL). It executes
-// the command provided in the method arguments and then passes the output to inspectProcessOutputForRecentlyUsedShell
-// for evaluation.
-//
-// It receives two arguments:
-// - defaultShell : default shell to revert back to in case it's unable to detect.
-// - command: command to be executed
-// - args: a string array containing command arguments
-//
-// It returns a string value representing current shell.
-func detectShellByInvokingCommand(defaultShell string, command string, args []string) string {
-	stdOut, _, err := CommandRunner.Run(command, args...)
-	if err != nil {
-		return defaultShell
-	}
-
-	detectedShell := inspectProcessOutputForRecentlyUsedShell(stdOut)
-	if detectedShell == "" {
-		return defaultShell
-	}
-	logging.Debugf("Detected shell: %s", detectedShell)
-	return detectedShell
-}
-
-// inspectProcessOutputForRecentlyUsedShell inspects output of ps command to detect currently active shell session.
-//
-// It parses the output into a struct, filters process types by name then reverse sort it with pid and returns the first element.
-//
-// It takes one argument:
-//
-// - psCommandOutput: output of ps command executed on a particular shell session
-//
-// It returns:
-//
-//   - a string value (one of `zsh`, `bash` or `fish`) for current shell environment in use. If it's not able to determine
-//     underlying shell type, it returns and empty string.
-//
-// This method tries to check all processes open and filters out shell sessions (one of `zsh`, `bash` or `fish)
-// It then returns first shell process.
-//
-// For example, if ps command gives this output:
-//
-//	2908 ps
-//	2889 fish
-//	823 bash
-//
-// Then this method would return `fish` as it's the first shell process.
-func inspectProcessOutputForRecentlyUsedShell(psCommandOutput string) string {
-	type ProcessOutput struct {
-		processID int
-		output    string
-	}
-	var processOutputs []ProcessOutput
-	lines := strings.Split(psCommandOutput, "\n")
-	for _, line := range lines {
-		lineParts := strings.Split(strings.TrimSpace(line), " ")
-		if len(lineParts) == 2 && (strings.Contains(lineParts[1], "zsh") ||
-			strings.Contains(lineParts[1], "bash") ||
-			strings.Contains(lineParts[1], "fish")) {
-			parsedProcessID, err := strconv.Atoi(lineParts[0])
-			if err == nil {
-				processOutputs = append(processOutputs, ProcessOutput{
-					processID: parsedProcessID,
-					output:    lineParts[1],
-				})
-			}
-		}
-	}
-	// Reverse sort the processes by PID (higher to lower)
-	sort.Slice(processOutputs, func(i, j int) bool {
-		return processOutputs[i].processID > processOutputs[j].processID
-	})
-
-	if len(processOutputs) > 0 {
-		return processOutputs[0].output
-	}
-	return ""
-}

pkg/os/shell/shell_test.go

@@ -179,50 +179,3 @@ func TestConvertToWindowsSubsystemLinuxPath(t *testing.T) {
 	assert.Equal(t, "wsl", mockCommandExecutor.commandName)
 	assert.Equal(t, []string{"-e", "bash", "-c", "wslpath -a 'C:\\Users\\foo\\.crc\\bin\\oc'"}, mockCommandExecutor.commandArgs)
 }
-
-func TestInspectProcessForRecentlyUsedShell(t *testing.T) {
-	tests := []struct {
-		name              string
-		psCommandOutput   string
-		expectedShellType string
-	}{
-		{
-			"nothing provided, then return empty string",
-			"",
-			"",
-		},
-		{
-			"bash shell, then detect bash shell",
-			"  31162 ps\n  435 bash",
-			"bash",
-		},
-		{
-			"zsh shell, then detect zsh shell",
-			"  31259 ps\n31253 zsh",
-			"zsh",
-		},
-		{
-			"fish shell, then detect fish shell",
-			"  31372 ps\n  31352 fish",
-			"fish",
-		},
-		{"bash and zsh shell, then detect zsh with more recent process id",
-			"  31259 ps\n  31253 zsh\n  435 bash",
-			"zsh",
-		},
-		{"bash and fish shell, then detect fish shell with more recent process id",
-			"    31372 ps\n  31352 fish\n  435 bash",
-			"fish",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			// Given + When
-			result := inspectProcessOutputForRecentlyUsedShell(tt.psCommandOutput)
-			// Then
-			if result != tt.expectedShellType {
-				t.Errorf("%s inspectProcessOutputForRecentlyUsedShell() = %s; want %s", tt.name, result, tt.expectedShellType)
-			}
-		})
-	}
-}

pkg/os/shell/shell_unix.go

@@ -6,20 +6,86 @@ package shell
 import (
 	"errors"
 	"fmt"
+	"os"
 	"path/filepath"
+
+	"github.com/shirou/gopsutil/v4/process"
+	"github.com/spf13/cast"
 )
 
 var (
-	ErrUnknownShell = errors.New("Error: Unknown shell")
+	ErrUnknownShell        = errors.New("Error: Unknown shell")
+	currentProcessSupplier = createCurrentProcess
 )
 
+// AbstractProcess is an interface created to abstract operations of the gopsutil library
+// It is created so that we can override the behavior while writing unit tests by providing
+// a mock implementation.
+type AbstractProcess interface {
+	Name() (string, error)
+	Parent() (AbstractProcess, error)
+}
+
+// RealProcess is a wrapper implementation of AbstractProcess to wrap around the gopsutil library's
+// process.Process object. This implementation is used in production code.
+type RealProcess struct {
+	*process.Process
+}
+
+func (p *RealProcess) Parent() (AbstractProcess, error) {
+	parentProcess, err := p.Process.Parent()
+	if err != nil {
+		return nil, err
+	}
+	return &RealProcess{parentProcess}, nil
+}
+
+func createCurrentProcess() AbstractProcess {
+	currentProcess, err := process.NewProcess(cast.ToInt32(os.Getpid()))
+	if err != nil {
+		return nil
+	}
+	return &RealProcess{currentProcess}
+}
+
 // detect detects user's current shell.
 func detect() (string, error) {
-	detectedShell := detectShellByInvokingCommand("", "ps", []string{"-o", "pid=,comm="})
+	detectedShell := detectShellByCheckingProcessTree(currentProcessSupplier())
 	if detectedShell == "" {
 		fmt.Printf("The default lines below are for a sh/bash shell, you can specify the shell you're using, with the --shell flag.\n\n")
 		return "", ErrUnknownShell
 	}
 
 	return filepath.Base(detectedShell), nil
 }
+
+// detectShellByCheckingProcessTree attempts to identify the shell being used by
+// examining the process tree starting from the given process ID. This function
+// traverses up to ProcessDepthLimit levels up the process hierarchy.
+// Parameters:
+//   - pid (int): The process ID to start checking from.
+//
+// Returns:
+//   - string: The name of the shell if found (e.g., "zsh", "bash", "fish");
+//     otherwise, an empty string is returned if no matching shell is detected
+//     or an error occurs during the process tree traversal.
+//
+// Examples:
+//
+//	shellName := detectShellByCheckingProcessTree(1234)
+func detectShellByCheckingProcessTree(p AbstractProcess) string {
+	for p != nil {
+		processName, err := p.Name()
+		if err != nil {
+			return ""
+		}
+		if processName == "zsh" || processName == "bash" || processName == "fish" {
+			return processName
+		}
+		p, err = p.Parent()
+		if err != nil {
+			return ""
+		}
+	}
+	return ""
+}