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fix: correct ANSI truncation #55

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Merged
llimllib merged 1 commit into from
May 26, 2026
Merged

fix: correct ANSI truncation #55

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49 changes: 25 additions & 24 deletions columns.go
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,16 +6,8 @@ import (
"os"
"path/filepath"
"strings"

"github.com/mattn/go-runewidth"
)

// truncateToWidth truncates a string to fit within the specified visual width,
// properly handling Unicode characters including diacritics
func truncateToWidth(s string, maxWidth int) string {
return runewidth.Truncate(s, maxWidth, "")
}

// Nerd Font icons for individual git status characters.
// See https://www.nerdfonts.com/cheat-sheet for the full icon list.
//
Expand Down Expand Up @@ -221,22 +213,24 @@ func renderStatus(out io.Writer, file *File, maxWidth int, rctx *RenderContext,
} else {
statusStr = file.status
}
visibleWidth := width(statusStr)
truncated := truncateToWidth(statusStr, maxWidth)
visibleWidth := width(truncated)
// Right-align: pad with spaces on the left
for i := 0; i < maxWidth-visibleWidth; i++ {
must(fmt.Fprintf(out, " "))
}
must(fmt.Fprintf(out, "%s", statusStr))
must(fmt.Fprintf(out, "%s", truncated))
// No right padding needed for status since it's right-aligned
}
}

// renderDiff renders the diff graph column
func renderDiff(out io.Writer, file *File, maxWidth int, rctx *RenderContext, isLast bool) {
if maxWidth > 0 {
must(fmt.Fprintf(out, "%s", file.diffStat))
truncated := truncateToWidth(file.diffStat, maxWidth)
must(fmt.Fprintf(out, "%s", truncated))
if !isLast {
for i := 0; i < maxWidth-width(file.diffStat); i++ {
for i := 0; i < maxWidth-width(truncated); i++ {
must(fmt.Fprintf(out, " "))
}
}
Expand All @@ -245,6 +239,9 @@ func renderDiff(out io.Writer, file *File, maxWidth int, rctx *RenderContext, is

// renderFilename renders the filename column with colors and hyperlinks
func renderFilename(out io.Writer, file *File, maxWidth int, rctx *RenderContext, isLast bool) {
truncatedName := truncateToWidth(file.Name(), maxWidth)
truncatedWidth := width(truncatedName)

if file.isDeleted {
must(fmt.Fprintf(out, "%s%s", RED, STRIKEOUT))
} else if file.isDir {
Expand All @@ -255,15 +252,15 @@ func renderFilename(out io.Writer, file *File, maxWidth int, rctx *RenderContext

// link the file name to the file's location (but not for deleted files)
if file.isDeleted {
must(fmt.Fprintf(out, "%s", file.Name()))
must(fmt.Fprintf(out, "%s", truncatedName))
} else {
fileURL := fmt.Sprintf("file://%s%s", must(os.Hostname()), filepath.Join(rctx.Dir, file.Name()))
must(fmt.Fprintf(out, "%s", link(fileURL, file.Name())))
must(fmt.Fprintf(out, "%s", link(fileURL, truncatedName)))
}

// pad spaces to the right up to maxWidth (unless this is the last column)
if !isLast {
for i := 0; i < maxWidth-width(file.Name()); i++ {
for i := 0; i < maxWidth-truncatedWidth; i++ {
must(fmt.Fprintf(out, " "))
}
}
Expand All @@ -278,7 +275,8 @@ func renderFilename(out io.Writer, file *File, maxWidth int, rctx *RenderContext
func renderShorthash(out io.Writer, file *File, maxWidth int, rctx *RenderContext, isLast bool) {
if maxWidth > 0 {
shortHash := file.shortHash
shortHashWidth := min(width(shortHash), maxWidth)
truncated := truncateToWidth(shortHash, maxWidth)
truncatedWidth := width(truncated)
var color string
if rctx.MonoHash {
color = CYAN
Expand All @@ -288,14 +286,14 @@ func renderShorthash(out io.Writer, file *File, maxWidth int, rctx *RenderContex

if len(rctx.GithubURL) > 0 && shortHash != "" {
commitURL := fmt.Sprintf("%s/commit/%s", rctx.GithubURL, file.hash)
must(fmt.Fprintf(out, "%s%s%s", color, link(commitURL, shortHash[:min(len(shortHash), maxWidth)]), RESET))
must(fmt.Fprintf(out, "%s%s%s", color, link(commitURL, truncated), RESET))
} else {
must(fmt.Fprintf(out, "%s%s%s", color, shortHash[:min(len(shortHash), maxWidth)], RESET))
must(fmt.Fprintf(out, "%s%s%s", color, truncated, RESET))
}

// pad spaces to the right up to maxWidth (unless this is the last column)
if !isLast {
for i := 0; i < maxWidth-shortHashWidth; i++ {
for i := 0; i < maxWidth-truncatedWidth; i++ {
must(fmt.Fprintf(out, " "))
}
}
Expand All @@ -311,16 +309,18 @@ func renderHash(out io.Writer, file *File, maxWidth int, rctx *RenderContext, is
} else {
color = hashToColor(file.hash)
}
truncated := truncateToWidth(file.hash, maxWidth)
truncatedWidth := width(truncated)
if len(rctx.GithubURL) > 0 && file.hash != "" {
commitURL := fmt.Sprintf("%s/commit/%s", rctx.GithubURL, file.hash)
must(fmt.Fprintf(out, "%s%s%s", color, link(commitURL, file.hash), RESET))
must(fmt.Fprintf(out, "%s%s%s", color, link(commitURL, truncated), RESET))
} else {
must(fmt.Fprintf(out, "%s%s%s", color, file.hash, RESET))
must(fmt.Fprintf(out, "%s%s%s", color, truncated, RESET))
}

// pad spaces to the right up to maxWidth (unless this is the last column)
if !isLast {
for i := 0; i < maxWidth-width(file.hash); i++ {
for i := 0; i < maxWidth-truncatedWidth; i++ {
must(fmt.Fprintf(out, " "))
}
}
Expand All @@ -329,10 +329,11 @@ func renderHash(out io.Writer, file *File, maxWidth int, rctx *RenderContext, is

// renderDate renders the date column
func renderDate(out io.Writer, file *File, maxWidth int, rctx *RenderContext, isLast bool) {
must(fmt.Fprintf(out, "%s", file.lastModified))
truncated := truncateToWidth(file.lastModified, maxWidth)
must(fmt.Fprintf(out, "%s", truncated))
// pad spaces to the right up to maxWidth (unless this is the last column)
if !isLast {
for i := 0; i < maxWidth-width(file.lastModified); i++ {
for i := 0; i < maxWidth-width(truncated); i++ {
must(fmt.Fprintf(out, " "))
}
}
Expand Down
158 changes: 1 addition & 157 deletions main.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,11 +14,7 @@ import (
"strconv"
"strings"
"sync"
"syscall"
"time"
"unsafe"

"github.com/mattn/go-runewidth"
)

const VERSION = "6.1.0"
Expand Down Expand Up @@ -158,76 +154,6 @@ func (f *File) Name() string {
return f.name
}

var (
BLUE = "\x1b[34m"
CYAN = "\x1b[36m"
GREEN = "\x1b[32m"
RED = "\x1b[31m"
RESET = "\x1b[0m"
YELLOW = "\x1b[33m"
STRIKEOUT = "\x1b[9m"
NOCOLOR = false
)

func init() {
if _, ok := os.LookupEnv("NO_COLOR"); ok {
NOCOLOR = true
BLUE = ""
CYAN = ""
GREEN = ""
RED = ""
RESET = ""
YELLOW = ""
STRIKEOUT = ""
}
}

// validHashColors contains pre-computed 8-bit terminal color codes
// from the 6x6x6 RGB cube (16-231), excluding colors that are too dark,
// too light, or too gray.
var validHashColors = []int{
18, 19, 20, 21, 24, 25, 26, 27, 28, 29,
30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
40, 41, 42, 43, 44, 45, 46, 47, 48, 49,
50, 51, 54, 55, 56, 57, 61, 62, 63, 64,
67, 68, 69, 70, 71, 72, 73, 74, 75, 76,
77, 78, 79, 80, 81, 82, 83, 84, 85, 86,
87, 88, 89, 90, 91, 92, 93, 94, 97, 98,
99, 100, 104, 105, 106, 107, 110, 111, 112, 113,
114, 115, 116, 117, 118, 119, 120, 121, 122, 123,
124, 125, 126, 127, 128, 129, 130, 131, 132, 133,
134, 135, 136, 137, 140, 141, 142, 143, 147, 148,
149, 150, 153, 154, 155, 156, 157, 158, 159, 160,
161, 162, 163, 164, 165, 166, 167, 168, 169, 170,
171, 172, 173, 174, 175, 176, 177, 178, 179, 180,
183, 184, 185, 186, 190, 191, 192, 193, 196, 197,
198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
208, 209, 210, 211, 212, 213, 214, 215, 216, 217,
218, 219, 220, 221, 222, 223, 226, 227, 228, 229,
}

// hashToColor generates a color code for a commit hash.
// It uses 8-bit terminal colors (\e[38;5;<n>m) from the pre-computed validHashColors.
func hashToColor(hash string) string {
if NOCOLOR {
return ""
}

if hash == "" {
return CYAN
}

// Calculate a numeric hash from the commit hash string
var h uint32
for i := 0; i < len(hash) && i < 8; i++ {
h = h*31 + uint32(hash[i])
}

// Select a color from the pre-computed valid colors using the hash
colorCode := validHashColors[h%uint32(len(validHashColors))]
return fmt.Sprintf("\x1b[38;5;%dm", colorCode)
}

func must[T any](a T, e error) T {
if e != nil {
panic(e)
Expand Down Expand Up @@ -607,7 +533,7 @@ func run() int {
formatColumns = AllColumns()
}

maxWidth := columns(os.Stdout.Fd())
maxWidth := terminalColumns(os.Stdout.Fd())
if maxWidth == 0 {
maxWidth = 80 // default when not a TTY
}
Expand Down Expand Up @@ -756,88 +682,6 @@ func parseFormat(formatStr string) []Column {
return columns
}

func link(url string, name string) string {
// hyperlink format: \e]8;;<url>\e\<link text>\e]8;;\e\
return fmt.Sprintf("\x1b]8;;%s\x1b\\%s\x1b]8;;\x1b\\", url, name)
}

func linkify(commitMsg string, github string, hash string) string {
issueRe := regexp.MustCompile(`#(\d+)`)
issueIx := issueRe.FindStringIndex(commitMsg)
out := make([]string, 0, 16)
for issueIx != nil {
commitURL := fmt.Sprintf("%s/commit/%s", github, hash)
out = append(out, link(commitURL, commitMsg[:issueIx[0]]))

issueURL := fmt.Sprintf("%s/pull/%s", github, commitMsg[issueIx[0]+1:issueIx[1]])
issueText := fmt.Sprintf("%s%s%s", BLUE, commitMsg[issueIx[0]:issueIx[1]], RESET)
out = append(out, link(issueURL, issueText))

commitMsg = commitMsg[issueIx[1]:]
issueIx = issueRe.FindStringIndex(commitMsg)
}
out = append(out, link(fmt.Sprintf("%s/commit/%s", github, hash), commitMsg))

return strings.Join(out, "")
}

// width returns the printable width of a string in a terminal, by ignoring
// ansi sequences. This version assumes all characters have a width of 1, which
// is not true in general but is true in this program. modified from:
// https://github.com/muesli/ansi/blob/276c6243b/buffer.go#L21
func width(s string) int {
// Use runewidth to properly handle Unicode characters including diacritics
return runewidth.StringWidth(stripANSI(s))
}

// stripANSI removes ANSI escape codes from a string for width calculation
func stripANSI(s string) string {
var result strings.Builder
var i int
for i < len(s) {
if i < len(s)-1 && s[i] == '\x1b' {
// Check for OSC sequences (hyperlinks): \x1b]8;;...\x1b\\
if s[i+1] == ']' {
// Find the ST (String Terminator): \x1b\\
end := strings.Index(s[i:], "\x1b\\")
if end != -1 {
i += end + 2 // Skip past the entire OSC sequence
continue
}
}
// Check for CSI sequences: \x1b[...letter
if s[i+1] == '[' {
i += 2
for i < len(s) {
// @, A-Z, a-z terminate the escape
if (s[i] >= 0x40 && s[i] <= 0x5a) || (s[i] >= 0x61 && s[i] <= 0x7a) {
i++
break
}
i++
}
continue
}
}
result.WriteByte(s[i])
i++
}
return result.String()
}

type windowSize struct {
rows uint16
cols uint16
}

// from https://github.com/epam/hubctl/blob/6f86e6663/cmd/hub/lifecycle/terminal.go#L59
func columns(fd uintptr) int {
var sz windowSize
_, _, _ = syscall.Syscall(syscall.SYS_IOCTL,
fd, uintptr(syscall.TIOCGWINSZ), uintptr(unsafe.Pointer(&sz)))
return int(sz.cols)
}

// Pulled straight from git:
// https://github.com/git/git/blob/d4cc1ec3/diff.c#L2862-L2874
func scaleLinear(n int, width int, maxChange int) int {
Expand Down
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