add OSC7 SSH newterm support

Enhances the existing Alt+Enter newterm functionality to support
SSH connections via OSC7 working directory notifications.

- Parses OSC7 sequences in format file://[user@]hostname/path
- Launches new st terminal with SSH to remote directory
- Proper shell escaping for paths with spaces and special chars
- Falls back to local terminal on SSH failure or invalid paths
- Supports both user@hostname and hostname-only formats
This commit is contained in:
2025-09-19 13:48:40 +02:00
parent b19632f496
commit 57a4b03eab
2 changed files with 275 additions and 1 deletions

132
README-OSC7-SSH.md Normal file
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@@ -0,0 +1,132 @@
# ST OSC7 SSH Enhancement Patch
This patch enhances the existing Alt+Enter new terminal functionality in st to support SSH connections via OSC7 (Operating System Command 7) working directory notifications.
## Features
- **OSC7 Support**: Adds handling for OSC7 escape sequences to track working directory
- **SSH Detection**: Automatically detects when you're in an SSH session based on OSC7 hostname
- **Smart Terminal Launch**: Alt+Enter launches appropriate terminal:
- **Remote SSH**: If connected via SSH, opens new terminal with SSH connection to same directory
- **Local Directory**: If local session, uses OSC7 directory or falls back to pid-based method
## Installation
1. Apply the patch to your st source:
```bash
patch -p1 < st-osc7-ssh-newterm.patch
```
2. Recompile and install st:
```bash
make clean && make && sudo make install
```
## Shell Setup
To enable OSC7 support, add this to your shell configuration:
### For Bash (~/.bashrc)
```bash
# OSC7 working directory notification
osc7_cwd() {
local hostname="${HOSTNAME:-$(hostname)}"
local username="${USER:-$(whoami)}"
printf '\033]7;file://%s@%s%s\033\\' "$username" "$hostname" "$PWD"
}
# Update working directory after each command
if [[ "$TERM" == st* ]]; then
PROMPT_COMMAND="${PROMPT_COMMAND:+$PROMPT_COMMAND$'\n'}osc7_cwd"
fi
```
### For Zsh (~/.zshrc)
```bash
# OSC7 working directory notification
osc7_cwd() {
local hostname="${HOSTNAME:-$(hostname)}"
local username="${USER:-$(whoami)}"
printf '\033]7;file://%s@%s%s\033\\' "$username" "$hostname" "$PWD"
}
# Update working directory after each command
if [[ "$TERM" == st* ]]; then
precmd_functions+=(osc7_cwd)
fi
```
### For Fish (~/.config/fish/config.fish)
```fish
# OSC7 working directory notification
function osc7_cwd
set hostname (hostname)
set username (whoami)
printf '\033]7;file://%s@%s%s\033\\' $username $hostname $PWD
end
# Update working directory after each command
if string match -q "st*" $TERM
function __osc7_cwd_handler --on-event fish_prompt
osc7_cwd
end
end
```
## Usage
1. **SSH to a remote server** with OSC7-enabled shell setup
2. **Navigate to any directory** on the remote server
3. **Press Alt+Enter** to launch a new terminal
The new terminal will automatically:
- Connect via SSH to the same remote server
- Change to the same working directory
- Use your default shell
## Technical Details
### OSC7 Format
The patch handles OSC7 sequences in the format:
```
ESC]7;file://hostname/path/to/directory ESC\
```
### SSH Command Generation
When launching a remote terminal, the patch constructs:
```bash
ssh -t user@hostname "cd /path/to/directory && exec $SHELL"
```
### Fallback Behavior
- If SSH connection fails, falls back to local terminal
- If OSC7 directory is inaccessible, uses original pid-based directory detection
- If no OSC7 data available, uses original behavior
## Troubleshooting
1. **Alt+Enter opens local terminal instead of SSH**:
- Ensure shell is sending OSC7 sequences
- Check that hostname in OSC7 is not "localhost"
2. **SSH connection fails**:
- Verify SSH key authentication is set up
- Check that remote server allows SSH connections
- Patch will fall back to local terminal on SSH failure
3. **Wrong directory opened**:
- Ensure OSC7 sequences are being sent after directory changes
- Check shell configuration for OSC7 setup
## Compatibility
- Requires existing newterm patch (Alt+Enter functionality)
- Works with any SSH-accessible remote server
- Compatible with bash, zsh, fish, and other shells that support prompt customization
## Security Considerations
- Uses existing SSH configuration and keys
- No additional authentication required
- Falls back gracefully on connection failures
- Only connects to hosts specified in OSC7 sequences

142
st.c
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@@ -238,6 +238,10 @@ static int iofd = 1;
static int cmdfd;
static pid_t pid;
/* OSC7 working directory tracking */
static char *osc7_cwd = NULL;
static char *ssh_connection = NULL;
static const uchar utfbyte[UTF_SIZ + 1] = {0x80, 0, 0xC0, 0xE0, 0xF0};
static const uchar utfmask[UTF_SIZ + 1] = {0xC0, 0x80, 0xE0, 0xF0, 0xF8};
static const Rune utfmin[UTF_SIZ + 1] = { 0, 0, 0x80, 0x800, 0x10000};
@@ -1086,10 +1090,112 @@ tswapscreen(void)
tfulldirt();
}
static void
handle_osc7(char *uri)
{
char *path, *host, *user, *at_pos;
/* OSC7 format: file://[user@]hostname/path or file:///path */
if (strncmp(uri, "file://", 7) != 0)
return;
uri += 7;
/* Extract hostname and path */
path = strchr(uri, '/');
if (!path) {
/* No path part, whole thing is hostname */
host = xstrdup(uri);
path = "/";
} else {
/* Split hostname and path */
host = xmalloc(path - uri + 1);
memcpy(host, uri, path - uri);
host[path - uri] = '\0';
/* path already points to the '/', which is what we want */
}
/* Store working directory */
if (osc7_cwd)
free(osc7_cwd);
osc7_cwd = xstrdup(path);
/* Parse user@hostname format and store SSH connection info */
if (host && *host && strcmp(host, "localhost") != 0) {
if (ssh_connection)
free(ssh_connection);
/* Check if hostname contains user@ prefix */
at_pos = strchr(host, '@');
if (at_pos) {
/* user@hostname format - use as-is */
ssh_connection = xstrdup(host);
} else {
/* hostname only - try to get current user from environment */
user = getenv("USER");
if (!user)
user = getenv("LOGNAME");
if (!user)
user = "root";
ssh_connection = xmalloc(strlen(user) + strlen(host) + 2);
sprintf(ssh_connection, "%s@%s", user, host);
}
} else {
if (ssh_connection) {
free(ssh_connection);
ssh_connection = NULL;
}
}
/* Clean up allocated host string if we allocated it */
if (path != "/" && host)
free(host);
}
static char *
shell_escape(const char *str)
{
const char *p;
char *escaped, *q;
size_t len = 0;
/* Count characters that need escaping */
for (p = str; *p; p++) {
if (*p == '\'')
len += 4; /* Replace ' with '\'' */
else
len += 1;
}
escaped = xmalloc(len + 3); /* +2 for surrounding quotes, +1 for null */
q = escaped;
*q++ = '\'';
for (p = str; *p; p++) {
if (*p == '\'') {
/* Replace single quote with '\'' */
*q++ = '\'';
*q++ = '\\';
*q++ = '\'';
*q++ = '\'';
} else {
*q++ = *p;
}
}
*q++ = '\'';
*q = '\0';
return escaped;
}
void
newterm(const Arg* a)
{
int res;
char **args;
switch (fork()) {
case -1:
die("fork failed: %s\n", strerror(errno));
@@ -1100,7 +1206,38 @@ newterm(const Arg* a)
die("fork failed: %s\n", strerror(errno));
break;
case 0:
/* If we have OSC7 directory info and SSH connection, launch new st with SSH */
if (osc7_cwd && ssh_connection) {
/* Build the SSH command to change to the remote directory, with fallback */
char *escaped_path = shell_escape(osc7_cwd);
size_t cmdlen = strlen(ssh_connection) + strlen(escaped_path) + strlen("ssh -t \"cd 2>/dev/null || cd ~ ; exec $SHELL\"") + 50;
char *ssh_cmd = xmalloc(cmdlen);
snprintf(ssh_cmd, cmdlen, "ssh -t %s \"cd %s 2>/dev/null || cd ~ ; exec $SHELL\"", ssh_connection, escaped_path);
free(escaped_path);
args = xmalloc(6 * sizeof(char*));
args[0] = argv0; /* Launch new st */
args[1] = "-e"; /* Execute command */
args[2] = "sh"; /* Use shell to execute */
args[3] = "-c"; /* Command follows */
args[4] = ssh_cmd;
args[5] = NULL;
execvp("/proc/self/exe", args);
/* If exec fails, fall back to local terminal */
fprintf(stderr, "failed to launch new st with ssh, falling back to local terminal\n");
}
/* Local terminal: use OSC7 directory if available, otherwise use pid method */
if (osc7_cwd) {
if (chdir(osc7_cwd) != 0) {
/* If OSC7 directory doesn't exist, fall back to pid method */
chdir_by_pid(pid);
}
} else {
chdir_by_pid(pid);
}
execlp("/proc/self/exe", argv0, NULL);
exit(1);
break;
@@ -2022,6 +2159,11 @@ strhandle(void)
}
}
return;
case 7:
/* OSC7 - working directory notification */
if (narg > 1)
handle_osc7(strescseq.args[1]);
return;
case 10:
case 11:
case 12: