File: //home/ubuntu/neovim/src/nvim/os/shell.c
#include <assert.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <uv.h>
#include "auto/config.h"
#include "klib/kvec.h"
#include "nvim/ascii_defs.h"
#include "nvim/buffer_defs.h"
#include "nvim/charset.h"
#include "nvim/errors.h"
#include "nvim/eval.h"
#include "nvim/eval/typval_defs.h"
#include "nvim/event/defs.h"
#include "nvim/event/libuv_process.h"
#include "nvim/event/loop.h"
#include "nvim/event/multiqueue.h"
#include "nvim/event/process.h"
#include "nvim/event/rstream.h"
#include "nvim/event/stream.h"
#include "nvim/event/wstream.h"
#include "nvim/ex_cmds.h"
#include "nvim/fileio.h"
#include "nvim/gettext_defs.h"
#include "nvim/globals.h"
#include "nvim/macros_defs.h"
#include "nvim/main.h"
#include "nvim/mbyte.h"
#include "nvim/memline.h"
#include "nvim/memory.h"
#include "nvim/message.h"
#include "nvim/option_vars.h"
#include "nvim/os/fs.h"
#include "nvim/os/os_defs.h"
#include "nvim/os/shell.h"
#include "nvim/os/signal.h"
#include "nvim/os/time.h"
#include "nvim/path.h"
#include "nvim/pos_defs.h"
#include "nvim/profile.h"
#include "nvim/state_defs.h"
#include "nvim/strings.h"
#include "nvim/tag.h"
#include "nvim/types_defs.h"
#include "nvim/ui.h"
#include "nvim/vim_defs.h"
#define NS_1_SECOND 1000000000U // 1 second, in nanoseconds
#define OUT_DATA_THRESHOLD 1024 * 10U // 10KB, "a few screenfuls" of data.
#define SHELL_SPECIAL "\t \"&'$;<>()\\|"
#ifdef INCLUDE_GENERATED_DECLARATIONS
# include "os/shell.c.generated.h"
#endif
static void save_patterns(int num_pat, char **pat, int *num_file, char ***file)
{
*file = xmalloc((size_t)num_pat * sizeof(char *));
for (int i = 0; i < num_pat; i++) {
char *s = xstrdup(pat[i]);
// Be compatible with expand_filename(): halve the number of
// backslashes.
backslash_halve(s);
(*file)[i] = s;
}
*num_file = num_pat;
}
static bool have_wildcard(int num, char **file)
{
for (int i = 0; i < num; i++) {
if (path_has_wildcard(file[i])) {
return true;
}
}
return false;
}
static bool have_dollars(int num, char **file)
{
for (int i = 0; i < num; i++) {
if (vim_strchr(file[i], '$') != NULL) {
return true;
}
}
return false;
}
/// Performs wildcard pattern matching using the shell.
///
/// @param num_pat is the number of input patterns.
/// @param pat is an array of pointers to input patterns.
/// @param[out] num_file is pointer to number of matched file names.
/// Set to the number of pointers in *file.
/// @param[out] file is pointer to array of pointers to matched file names.
/// Memory pointed to by the initial value of *file will
/// not be freed.
/// Set to NULL if FAIL is returned. Otherwise points to
/// allocated memory.
/// @param flags is a combination of EW_* flags used in
/// expand_wildcards().
/// If matching fails but EW_NOTFOUND is set in flags or
/// there are no wildcards, the patterns from pat are
/// copied into *file.
///
/// @returns OK for success or FAIL for error.
int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, int flags)
FUNC_ATTR_NONNULL_ARG(3)
FUNC_ATTR_NONNULL_ARG(4)
{
int i;
size_t len;
char *p;
char *extra_shell_arg = NULL;
ShellOpts shellopts = kShellOptExpand | kShellOptSilent;
int j;
char *tempname;
#define STYLE_ECHO 0 // use "echo", the default
#define STYLE_GLOB 1 // use "glob", for csh
#define STYLE_VIMGLOB 2 // use "vimglob", for Posix sh
#define STYLE_PRINT 3 // use "print -N", for zsh
#define STYLE_BT 4 // `cmd` expansion, execute the pattern directly
#define STYLE_GLOBSTAR 5 // use extended shell glob for bash (this uses extended
// globbing functionality with globstar, needs bash > 4)
int shell_style = STYLE_ECHO;
int check_spaces;
static bool did_find_nul = false;
bool ampersand = false;
// vimglob() function to define for Posix shell
static char *sh_vimglob_func =
"vimglob() { while [ $# -ge 1 ]; do echo \"$1\"; shift; done }; vimglob >";
// vimglob() function with globstar setting enabled, only for bash >= 4.X
static char *sh_globstar_opt =
"[[ ${BASH_VERSINFO[0]} -ge 4 ]] && shopt -s globstar; ";
bool is_fish_shell =
#if defined(UNIX)
strncmp(invocation_path_tail(p_sh, NULL), "fish", 4) == 0;
#else
false;
#endif
*num_file = 0; // default: no files found
*file = NULL;
// If there are no wildcards, just copy the names to allocated memory.
// Saves a lot of time, because we don't have to start a new shell.
if (!have_wildcard(num_pat, pat)) {
save_patterns(num_pat, pat, num_file, file);
return OK;
}
// Don't allow any shell command in the sandbox.
if (sandbox != 0 && check_secure()) {
return FAIL;
}
// Don't allow the use of backticks in secure.
if (secure) {
for (i = 0; i < num_pat; i++) {
if (vim_strchr(pat[i], '`') != NULL
&& (check_secure())) {
return FAIL;
}
}
}
// get a name for the temp file
if ((tempname = vim_tempname()) == NULL) {
emsg(_(e_notmp));
return FAIL;
}
// Let the shell expand the patterns and write the result into the temp
// file.
// STYLE_BT: NL separated
// If expanding `cmd` execute it directly.
// STYLE_GLOB: NUL separated
// If we use *csh, "glob" will work better than "echo".
// STYLE_PRINT: NL or NUL separated
// If we use *zsh, "print -N" will work better than "glob".
// STYLE_VIMGLOB: NL separated
// If we use *sh*, we define "vimglob()".
// STYLE_GLOBSTAR: NL separated
// If we use *bash*, we define "vimglob() and enable globstar option".
// STYLE_ECHO: space separated.
// A shell we don't know, stay safe and use "echo".
if (num_pat == 1 && *pat[0] == '`'
&& (len = strlen(pat[0])) > 2
&& *(pat[0] + len - 1) == '`') {
shell_style = STYLE_BT;
} else if ((len = strlen(p_sh)) >= 3) {
if (strcmp(p_sh + len - 3, "csh") == 0) {
shell_style = STYLE_GLOB;
} else if (strcmp(p_sh + len - 3, "zsh") == 0) {
shell_style = STYLE_PRINT;
}
}
if (shell_style == STYLE_ECHO) {
if (strstr(path_tail(p_sh), "bash") != NULL) {
shell_style = STYLE_GLOBSTAR;
} else if (strstr(path_tail(p_sh), "sh") != NULL) {
shell_style = STYLE_VIMGLOB;
}
}
// Compute the length of the command. We need 2 extra bytes: for the
// optional '&' and for the NUL.
// Worst case: "unset nonomatch; print -N >" plus two is 29
len = strlen(tempname) + 29;
if (shell_style == STYLE_VIMGLOB) {
len += strlen(sh_vimglob_func);
} else if (shell_style == STYLE_GLOBSTAR) {
len += strlen(sh_vimglob_func) + strlen(sh_globstar_opt);
}
for (i = 0; i < num_pat; i++) {
// Count the length of the patterns in the same way as they are put in
// "command" below.
len++; // add space
for (j = 0; pat[i][j] != NUL; j++) {
if (vim_strchr(SHELL_SPECIAL, (uint8_t)pat[i][j]) != NULL) {
len++; // may add a backslash
}
len++;
}
}
if (is_fish_shell) {
len += sizeof("egin;" " end") - 1;
}
char *command = xmalloc(len);
// Build the shell command:
// - Set $nonomatch depending on EW_NOTFOUND (hopefully the shell
// recognizes this).
// - Add the shell command to print the expanded names.
// - Add the temp file name.
// - Add the file name patterns.
if (shell_style == STYLE_BT) {
// change `command; command& ` to (command; command )
if (is_fish_shell) {
STRCPY(command, "begin; ");
} else {
STRCPY(command, "(");
}
strcat(command, pat[0] + 1); // exclude first backtick
p = command + strlen(command) - 1;
if (is_fish_shell) {
*p-- = ';';
strcat(command, " end");
} else {
*p-- = ')'; // remove last backtick
}
while (p > command && ascii_iswhite(*p)) {
p--;
}
if (*p == '&') { // remove trailing '&'
ampersand = true;
*p = ' ';
}
strcat(command, ">");
} else {
STRCPY(command, "");
if (shell_style == STYLE_GLOB) {
// Assume the nonomatch option is valid only for csh like shells,
// otherwise, this may set the positional parameters for the shell,
// e.g. "$*".
if (flags & EW_NOTFOUND) {
strcat(command, "set nonomatch; ");
} else {
strcat(command, "unset nonomatch; ");
}
}
if (shell_style == STYLE_GLOB) {
strcat(command, "glob >");
} else if (shell_style == STYLE_PRINT) {
strcat(command, "print -N >");
} else if (shell_style == STYLE_VIMGLOB) {
strcat(command, sh_vimglob_func);
} else if (shell_style == STYLE_GLOBSTAR) {
strcat(command, sh_globstar_opt);
strcat(command, sh_vimglob_func);
} else {
strcat(command, "echo >");
}
}
strcat(command, tempname);
if (shell_style != STYLE_BT) {
for (i = 0; i < num_pat; i++) {
// Put a backslash before special
// characters, except inside ``.
bool intick = false;
p = command + strlen(command);
*p++ = ' ';
for (j = 0; pat[i][j] != NUL; j++) {
if (pat[i][j] == '`') {
intick = !intick;
} else if (pat[i][j] == '\\' && pat[i][j + 1] != NUL) {
// Remove a backslash, take char literally. But keep
// backslash inside backticks, before a special character
// and before a backtick.
if (intick
|| vim_strchr(SHELL_SPECIAL, (uint8_t)pat[i][j + 1]) != NULL
|| pat[i][j + 1] == '`') {
*p++ = '\\';
}
j++;
} else if (!intick
&& ((flags & EW_KEEPDOLLAR) == 0 || pat[i][j] != '$')
&& vim_strchr(SHELL_SPECIAL, (uint8_t)pat[i][j]) != NULL) {
// Put a backslash before a special character, but not
// when inside ``. And not for $var when EW_KEEPDOLLAR is
// set.
*p++ = '\\';
}
// Copy one character.
*p++ = pat[i][j];
}
*p = NUL;
}
}
if (flags & EW_SILENT) {
shellopts |= kShellOptHideMess;
}
if (ampersand) {
strcat(command, "&"); // put the '&' after the redirection
}
// Using zsh -G: If a pattern has no matches, it is just deleted from
// the argument list, otherwise zsh gives an error message and doesn't
// expand any other pattern.
if (shell_style == STYLE_PRINT) {
extra_shell_arg = "-G"; // Use zsh NULL_GLOB option
// If we use -f then shell variables set in .cshrc won't get expanded.
// vi can do it, so we will too, but it is only necessary if there is a "$"
// in one of the patterns, otherwise we can still use the fast option.
} else if (shell_style == STYLE_GLOB && !have_dollars(num_pat, pat)) {
extra_shell_arg = "-f"; // Use csh fast option
}
// execute the shell command
i = call_shell(command, shellopts, extra_shell_arg);
// When running in the background, give it some time to create the temp
// file, but don't wait for it to finish.
if (ampersand) {
os_delay(10, true);
}
xfree(command);
if (i) { // os_call_shell() failed
os_remove(tempname);
xfree(tempname);
// With interactive completion, the error message is not printed.
if (!(flags & EW_SILENT)) {
msg_putchar('\n'); // clear bottom line quickly
cmdline_row = Rows - 1; // continue on last line
msg(_(e_wildexpand), 0);
msg_start(); // don't overwrite this message
}
// If a `cmd` expansion failed, don't list `cmd` as a match, even when
// EW_NOTFOUND is given
if (shell_style == STYLE_BT) {
return FAIL;
}
goto notfound;
}
// read the names from the file into memory
FILE *fd = fopen(tempname, READBIN);
if (fd == NULL) {
// Something went wrong, perhaps a file name with a special char.
if (!(flags & EW_SILENT)) {
msg(_(e_wildexpand), 0);
msg_start(); // don't overwrite this message
}
xfree(tempname);
goto notfound;
}
int fseek_res = fseek(fd, 0, SEEK_END);
if (fseek_res < 0) {
xfree(tempname);
fclose(fd);
return FAIL;
}
int64_t templen = ftell(fd); // get size of temp file
if (templen < 0) {
xfree(tempname);
fclose(fd);
return FAIL;
}
#if 8 > SIZEOF_SIZE_T
assert(templen <= SIZE_MAX); // NOLINT(runtime/int)
#endif
len = (size_t)templen;
fseek(fd, 0, SEEK_SET);
char *buffer = xmalloc(len + 1);
// fread() doesn't terminate buffer with NUL;
// appropriate termination (not always NUL) is done below.
size_t readlen = fread(buffer, 1, len, fd);
fclose(fd);
os_remove(tempname);
if (readlen != len) {
// unexpected read error
semsg(_(e_notread), tempname);
xfree(tempname);
xfree(buffer);
return FAIL;
}
xfree(tempname);
// file names are separated with Space
if (shell_style == STYLE_ECHO) {
buffer[len] = '\n'; // make sure the buffer ends in NL
p = buffer;
for (i = 0; *p != '\n'; i++) { // count number of entries
while (*p != ' ' && *p != '\n') {
p++;
}
p = skipwhite(p); // skip to next entry
}
// file names are separated with NL
} else if (shell_style == STYLE_BT
|| shell_style == STYLE_VIMGLOB
|| shell_style == STYLE_GLOBSTAR) {
buffer[len] = NUL; // make sure the buffer ends in NUL
p = buffer;
for (i = 0; *p != NUL; i++) { // count number of entries
while (*p != '\n' && *p != NUL) {
p++;
}
if (*p != NUL) {
p++;
}
p = skipwhite(p); // skip leading white space
}
// file names are separated with NUL
} else {
// Some versions of zsh use spaces instead of NULs to separate
// results. Only do this when there is no NUL before the end of the
// buffer, otherwise we would never be able to use file names with
// embedded spaces when zsh does use NULs.
// When we found a NUL once, we know zsh is OK, set did_find_nul and
// don't check for spaces again.
check_spaces = false;
if (shell_style == STYLE_PRINT && !did_find_nul) {
// If there is a NUL, set did_find_nul, else set check_spaces
buffer[len] = NUL;
if (len && (int)strlen(buffer) < (int)len) {
did_find_nul = true;
} else {
check_spaces = true;
}
}
// Make sure the buffer ends with a NUL. For STYLE_PRINT there
// already is one, for STYLE_GLOB it needs to be added.
if (len && buffer[len - 1] == NUL) {
len--;
} else {
buffer[len] = NUL;
}
for (p = buffer; p < buffer + len; p++) {
if (*p == NUL || (*p == ' ' && check_spaces)) { // count entry
i++;
*p = NUL;
}
}
if (len) {
i++; // count last entry
}
}
assert(buffer[len] == NUL || buffer[len] == '\n');
if (i == 0) {
// Can happen when using /bin/sh and typing ":e $NO_SUCH_VAR^I".
// /bin/sh will happily expand it to nothing rather than returning an
// error; and hey, it's good to check anyway -- webb.
xfree(buffer);
goto notfound;
}
*num_file = i;
*file = xmalloc(sizeof(char *) * (size_t)i);
// Isolate the individual file names.
p = buffer;
for (i = 0; i < *num_file; i++) {
(*file)[i] = p;
// Space or NL separates
if (shell_style == STYLE_ECHO || shell_style == STYLE_BT
|| shell_style == STYLE_VIMGLOB || shell_style == STYLE_GLOBSTAR) {
while (!(shell_style == STYLE_ECHO && *p == ' ')
&& *p != '\n' && *p != NUL) {
p++;
}
if (p == buffer + len) { // last entry
*p = NUL;
} else {
*p++ = NUL;
p = skipwhite(p); // skip to next entry
}
} else { // NUL separates
while (*p && p < buffer + len) { // skip entry
p++;
}
p++; // skip NUL
}
}
// Move the file names to allocated memory.
for (j = 0, i = 0; i < *num_file; i++) {
// Require the files to exist. Helps when using /bin/sh
if (!(flags & EW_NOTFOUND) && !os_path_exists((*file)[i])) {
continue;
}
// check if this entry should be included
bool dir = (os_isdir((*file)[i]));
if ((dir && !(flags & EW_DIR)) || (!dir && !(flags & EW_FILE))) {
continue;
}
// Skip files that are not executable if we check for that.
if (!dir && (flags & EW_EXEC)
&& !os_can_exe((*file)[i], NULL, !(flags & EW_SHELLCMD))) {
continue;
}
p = xmalloc(strlen((*file)[i]) + 1 + dir);
STRCPY(p, (*file)[i]);
if (dir) {
add_pathsep(p); // add '/' to a directory name
}
(*file)[j++] = p;
}
xfree(buffer);
*num_file = j;
if (*num_file == 0) { // rejected all entries
XFREE_CLEAR(*file);
goto notfound;
}
return OK;
notfound:
if (flags & EW_NOTFOUND) {
save_patterns(num_pat, pat, num_file, file);
return OK;
}
return FAIL;
}
/// Builds the argument vector for running the user-configured 'shell' (p_sh)
/// with an optional command prefixed by 'shellcmdflag' (p_shcf). E.g.:
///
/// ["shell", "-extra_args", "-shellcmdflag", "command with spaces"]
///
/// @param cmd Command string, or NULL to run an interactive shell.
/// @param extra_args Extra arguments to the shell, or NULL.
/// @return Newly allocated argument vector. Must be freed with shell_free_argv.
char **shell_build_argv(const char *cmd, const char *extra_args)
FUNC_ATTR_NONNULL_RET
{
size_t argc = tokenize(p_sh, NULL) + (cmd ? tokenize(p_shcf, NULL) : 0);
char **rv = xmalloc((argc + 4) * sizeof(*rv));
// Split 'shell'
size_t i = tokenize(p_sh, rv);
if (extra_args) {
rv[i++] = xstrdup(extra_args); // Push a copy of `extra_args`
}
if (cmd) {
i += tokenize(p_shcf, rv + i); // Split 'shellcmdflag'
rv[i++] = shell_xescape_xquote(cmd); // Copy (and escape) `cmd`.
}
rv[i] = NULL;
assert(rv[0]);
return rv;
}
/// Releases the memory allocated by `shell_build_argv`.
///
/// @param argv The argument vector.
void shell_free_argv(char **argv)
{
char **p = argv;
if (p == NULL) {
// Nothing was allocated, return
return;
}
while (*p != NULL) {
// Free each argument
xfree(*p);
p++;
}
xfree(argv);
}
/// Joins shell arguments from `argv` into a new string.
/// If the result is too long it is truncated with ellipsis ("...").
///
/// @returns[allocated] `argv` joined to a string.
char *shell_argv_to_str(char **const argv)
FUNC_ATTR_NONNULL_ALL
{
size_t n = 0;
char **p = argv;
char *rv = xcalloc(256, sizeof(*rv));
const size_t maxsize = (256 * sizeof(*rv));
if (*p == NULL) {
return rv;
}
while (*p != NULL) {
xstrlcat(rv, "'", maxsize);
xstrlcat(rv, *p, maxsize);
n = xstrlcat(rv, "' ", maxsize);
if (n >= maxsize) {
break;
}
p++;
}
if (n < maxsize) {
rv[n - 1] = NUL;
} else {
// Command too long, show ellipsis: "/bin/bash 'foo' 'bar'..."
rv[maxsize - 4] = '.';
rv[maxsize - 3] = '.';
rv[maxsize - 2] = '.';
rv[maxsize - 1] = NUL;
}
return rv;
}
/// Calls the user-configured 'shell' (p_sh) for running a command or wildcard
/// expansion.
///
/// @param cmd The command to execute, or NULL to run an interactive shell.
/// @param opts Options that control how the shell will work.
/// @param extra_args Extra arguments to the shell, or NULL.
///
/// @return shell command exit code
int os_call_shell(char *cmd, ShellOpts opts, char *extra_args)
{
StringBuilder input = KV_INITIAL_VALUE;
char *output = NULL;
char **output_ptr = NULL;
int current_state = State;
bool forward_output = true;
// While the child is running, ignore terminating signals
signal_reject_deadly();
if (opts & (kShellOptHideMess | kShellOptExpand)) {
forward_output = false;
} else {
State = MODE_EXTERNCMD;
if (opts & kShellOptWrite) {
read_input(&input);
}
if (opts & kShellOptRead) {
output_ptr = &output;
forward_output = false;
} else if (opts & kShellOptDoOut) {
// Caller has already redirected output
forward_output = false;
}
}
size_t nread;
int exitcode = do_os_system(shell_build_argv(cmd, extra_args),
input.items, input.size, output_ptr, &nread,
emsg_silent, forward_output);
kv_destroy(input);
if (output) {
write_output(output, nread, true);
xfree(output);
}
if (!emsg_silent && exitcode != 0 && !(opts & kShellOptSilent)) {
msg_puts(_("\nshell returned "));
msg_outnum(exitcode);
msg_putchar('\n');
}
State = current_state;
signal_accept_deadly();
return exitcode;
}
/// os_call_shell() wrapper. Handles 'verbose', :profile, and v:shell_error.
/// Invalidates cached tags.
///
/// @return shell command exit code
int call_shell(char *cmd, ShellOpts opts, char *extra_shell_arg)
{
int retval;
proftime_T wait_time;
if (p_verbose > 3) {
verbose_enter();
smsg(0, _("Executing command: \"%s\""), cmd == NULL ? p_sh : cmd);
msg_putchar('\n');
verbose_leave();
}
if (do_profiling == PROF_YES) {
prof_child_enter(&wait_time);
}
if (*p_sh == NUL) {
emsg(_(e_shellempty));
retval = -1;
} else {
// The external command may update a tags file, clear cached tags.
tag_freematch();
retval = os_call_shell(cmd, opts, extra_shell_arg);
}
set_vim_var_nr(VV_SHELL_ERROR, (varnumber_T)retval);
if (do_profiling == PROF_YES) {
prof_child_exit(&wait_time);
}
return retval;
}
/// Get the stdout of an external command.
/// If "ret_len" is NULL replace NUL characters with NL. When "ret_len" is not
/// NULL store the length there.
///
/// @param cmd command to execute
/// @param infile optional input file name
/// @param flags can be kShellOptSilent or 0
/// @param ret_len length of the stdout
///
/// @return an allocated string, or NULL for error.
char *get_cmd_output(char *cmd, char *infile, ShellOpts flags, size_t *ret_len)
{
char *buffer = NULL;
if (check_secure()) {
return NULL;
}
// get a name for the temp file
char *tempname = vim_tempname();
if (tempname == NULL) {
emsg(_(e_notmp));
return NULL;
}
// Add the redirection stuff
char *command = make_filter_cmd(cmd, infile, tempname);
// Call the shell to execute the command (errors are ignored).
// Don't check timestamps here.
no_check_timestamps++;
call_shell(command, kShellOptDoOut | kShellOptExpand | flags, NULL);
no_check_timestamps--;
xfree(command);
// read the names from the file into memory
FILE *fd = os_fopen(tempname, READBIN);
if (fd == NULL) {
semsg(_(e_notopen), tempname);
goto done;
}
fseek(fd, 0, SEEK_END);
size_t len = (size_t)ftell(fd); // get size of temp file
fseek(fd, 0, SEEK_SET);
buffer = xmalloc(len + 1);
size_t i = fread(buffer, 1, len, fd);
fclose(fd);
os_remove(tempname);
if (i != len) {
semsg(_(e_notread), tempname);
XFREE_CLEAR(buffer);
} else if (ret_len == NULL) {
// Change NUL into SOH, otherwise the string is truncated.
for (i = 0; i < len; i++) {
if (buffer[i] == NUL) {
buffer[i] = 1;
}
}
buffer[len] = NUL; // make sure the buffer is terminated
} else {
*ret_len = len;
}
done:
xfree(tempname);
return buffer;
}
/// os_system - synchronously execute a command in the shell
///
/// example:
/// char *output = NULL;
/// size_t nread = 0;
/// char *argv[] = {"ls", "-la", NULL};
/// int exitcode = os_system(argv, NULL, 0, &output, &nread);
///
/// @param argv The commandline arguments to be passed to the shell. `argv`
/// will be consumed.
/// @param input The input to the shell (NULL for no input), passed to the
/// stdin of the resulting process.
/// @param len The length of the input buffer (not used if `input` == NULL)
/// @param[out] output Pointer to a location where the output will be
/// allocated and stored. Will point to NULL if the shell
/// command did not output anything. If NULL is passed,
/// the shell output will be ignored.
/// @param[out] nread the number of bytes in the returned buffer (if the
/// returned buffer is not NULL)
/// @return the return code of the process, -1 if the process couldn't be
/// started properly
int os_system(char **argv, const char *input, size_t len, char **output,
size_t *nread) FUNC_ATTR_NONNULL_ARG(1)
{
return do_os_system(argv, input, len, output, nread, true, false);
}
static int do_os_system(char **argv, const char *input, size_t len, char **output, size_t *nread,
bool silent, bool forward_output)
{
out_data_decide_throttle(0); // Initialize throttle decider.
out_data_ring(NULL, 0); // Initialize output ring-buffer.
bool has_input = (input != NULL && input[0] != NUL);
// the output buffer
StringBuilder buf = KV_INITIAL_VALUE;
stream_read_cb data_cb = system_data_cb;
if (nread) {
*nread = 0;
}
if (forward_output) {
data_cb = out_data_cb;
} else if (!output) {
data_cb = NULL;
}
// Copy the program name in case we need to report an error.
char prog[MAXPATHL];
xstrlcpy(prog, argv[0], MAXPATHL);
LibuvProcess uvproc = libuv_process_init(&main_loop, &buf);
Process *proc = &uvproc.process;
MultiQueue *events = multiqueue_new_child(main_loop.events);
proc->events = events;
proc->argv = argv;
int status = process_spawn(proc, has_input, true, true);
if (status) {
loop_poll_events(&main_loop, 0);
// Failed, probably 'shell' is not executable.
if (!silent) {
msg_puts(_("\nshell failed to start: "));
msg_outtrans(os_strerror(status), 0);
msg_puts(": ");
msg_outtrans(prog, 0);
msg_putchar('\n');
}
multiqueue_free(events);
return -1;
}
// Note: unlike process events, stream events are not queued, as we want to
// deal with stream events as fast a possible. It prevents closing the
// streams while there's still data in the OS buffer (due to the process
// exiting before all data is read).
if (has_input) {
wstream_init(&proc->in, 0);
}
rstream_init(&proc->out);
rstream_start(&proc->out, data_cb, &buf);
rstream_init(&proc->err);
rstream_start(&proc->err, data_cb, &buf);
// write the input, if any
if (has_input) {
WBuffer *input_buffer = wstream_new_buffer((char *)input, len, 1, NULL);
if (!wstream_write(&proc->in, input_buffer)) {
// couldn't write, stop the process and tell the user about it
process_stop(proc);
return -1;
}
// close the input stream after everything is written
wstream_set_write_cb(&proc->in, shell_write_cb, NULL);
}
// Invoke busy_start here so LOOP_PROCESS_EVENTS_UNTIL will not change the
// busy state.
ui_busy_start();
ui_flush();
if (forward_output) {
msg_sb_eol();
msg_start();
msg_no_more = true;
lines_left = -1;
}
int exitcode = process_wait(proc, -1, NULL);
if (!got_int && out_data_decide_throttle(0)) {
// Last chunk of output was skipped; display it now.
out_data_ring(NULL, SIZE_MAX);
}
if (forward_output) {
// caller should decide if wait_return() is invoked
no_wait_return++;
msg_end();
no_wait_return--;
msg_no_more = false;
}
ui_busy_stop();
// prepare the out parameters if requested
if (output) {
assert(nread);
if (buf.size == 0) {
// no data received from the process, return NULL
*output = NULL;
*nread = 0;
kv_destroy(buf);
} else {
*nread = buf.size;
// NUL-terminate to make the output directly usable as a C string
kv_push(buf, NUL);
*output = buf.items;
}
}
assert(multiqueue_empty(events));
multiqueue_free(events);
return exitcode;
}
static size_t system_data_cb(RStream *stream, const char *buf, size_t count, void *data, bool eof)
{
StringBuilder *dbuf = data;
kv_concat_len(*dbuf, buf, count);
return count;
}
/// Tracks output received for the current executing shell command, and displays
/// a pulsing "..." when output should be skipped. Tracking depends on the
/// synchronous/blocking nature of ":!".
///
/// Purpose:
/// 1. CTRL-C is more responsive. #1234 #5396
/// 2. Improves performance of :! (UI, esp. TUI, is the bottleneck).
/// 3. Avoids OOM during long-running, spammy :!.
///
/// Vim does not need this hack because:
/// 1. :! in terminal-Vim runs in cooked mode, so CTRL-C is caught by the
/// terminal and raises SIGINT out-of-band.
/// 2. :! in terminal-Vim uses a tty (Nvim uses pipes), so commands
/// (e.g. `git grep`) may page themselves.
///
/// @param size Length of data, used with internal state to decide whether
/// output should be skipped. size=0 resets the internal state and
/// returns the previous decision.
///
/// @returns true if output should be skipped and pulse was displayed.
/// Returns the previous decision if size=0.
static bool out_data_decide_throttle(size_t size)
{
static uint64_t started = 0; // Start time of the current throttle.
static size_t received = 0; // Bytes observed since last throttle.
static size_t visit = 0; // "Pulse" count of the current throttle.
static char pulse_msg[] = { ' ', ' ', ' ', NUL };
if (!size) {
bool previous_decision = (visit > 0);
started = received = visit = 0;
return previous_decision;
}
received += size;
if (received < OUT_DATA_THRESHOLD
// Display at least the first chunk of output even if it is big.
|| (!started && received < size + 1000)) {
return false;
} else if (!visit) {
started = os_hrtime();
} else {
uint64_t since = os_hrtime() - started;
if (since < (visit * (NS_1_SECOND / 10))) {
return true;
}
if (since > (3 * NS_1_SECOND)) {
received = visit = 0;
return false;
}
}
visit++;
// Pulse "..." at the bottom of the screen.
size_t tick = visit % 4;
pulse_msg[0] = (tick > 0) ? '.' : ' ';
pulse_msg[1] = (tick > 1) ? '.' : ' ';
pulse_msg[2] = (tick > 2) ? '.' : ' ';
if (visit == 1) {
msg_puts("...\n");
}
msg_putchar('\r'); // put cursor at start of line
msg_puts(pulse_msg);
msg_putchar('\r');
ui_flush();
return true;
}
/// Saves output in a quasi-ringbuffer. Used to ensure the last ~page of
/// output for a shell-command is always displayed.
///
/// Init mode: Resets the internal state.
/// output = NULL
/// size = 0
/// Print mode: Displays the current saved data.
/// output = NULL
/// size = SIZE_MAX
///
/// @param output Data to save, or NULL to invoke a special mode.
/// @param size Length of `output`.
static void out_data_ring(const char *output, size_t size)
{
#define MAX_CHUNK_SIZE (OUT_DATA_THRESHOLD / 2)
static char last_skipped[MAX_CHUNK_SIZE]; // Saved output.
static size_t last_skipped_len = 0;
assert(output != NULL || (size == 0 || size == SIZE_MAX));
if (output == NULL && size == 0) { // Init mode
last_skipped_len = 0;
return;
}
if (output == NULL && size == SIZE_MAX) { // Print mode
out_data_append_to_screen(last_skipped, &last_skipped_len, true);
return;
}
// This is basically a ring-buffer...
if (size >= MAX_CHUNK_SIZE) { // Save mode
size_t start = size - MAX_CHUNK_SIZE;
memcpy(last_skipped, output + start, MAX_CHUNK_SIZE);
last_skipped_len = MAX_CHUNK_SIZE;
} else if (size > 0) {
// Length of the old data that can be kept.
size_t keep_len = MIN(last_skipped_len, MAX_CHUNK_SIZE - size);
size_t keep_start = last_skipped_len - keep_len;
// Shift the kept part of the old data to the start.
if (keep_start) {
memmove(last_skipped, last_skipped + keep_start, keep_len);
}
// Copy the entire new data to the remaining space.
memcpy(last_skipped + keep_len, output, size);
last_skipped_len = keep_len + size;
}
}
/// Continue to append data to last screen line.
///
/// @param output Data to append to screen lines.
/// @param count Size of data.
/// @param eof If true, there will be no more data output.
static void out_data_append_to_screen(const char *output, size_t *count, bool eof)
FUNC_ATTR_NONNULL_ALL
{
const char *p = output;
const char *end = output + *count;
while (p < end) {
if (*p == '\n' || *p == '\r' || *p == TAB || *p == BELL) {
msg_putchar_attr((uint8_t)(*p), 0);
p++;
} else {
// Note: this is not 100% precise:
// 1. we don't check if received continuation bytes are already invalid
// and we thus do some buffering that could be avoided
// 2. we don't compose chars over buffer boundaries, even if we see an
// incomplete UTF-8 sequence that could be composing with the last
// complete sequence.
// This will be corrected when we switch to vterm based implementation
int i = *p ? utfc_ptr2len_len(p, (int)(end - p)) : 1;
if (!eof && i == 1 && utf8len_tab_zero[*(uint8_t *)p] > (end - p)) {
*count = (size_t)(p - output);
goto end;
}
msg_outtrans_len(p, i, 0);
p += i;
}
}
end:
ui_flush();
}
static size_t out_data_cb(RStream *stream, const char *ptr, size_t count, void *data, bool eof)
{
if (count > 0 && out_data_decide_throttle(count)) { // Skip output above a threshold.
// Save the skipped output. If it is the final chunk, we display it later.
out_data_ring(ptr, count);
} else if (count > 0) {
out_data_append_to_screen(ptr, &count, eof);
}
return count;
}
/// Parses a command string into a sequence of words, taking quotes into
/// consideration.
///
/// @param str The command string to be parsed
/// @param argv The vector that will be filled with copies of the parsed
/// words. It can be NULL if the caller only needs to count words.
/// @return The number of words parsed.
static size_t tokenize(const char *const str, char **const argv)
FUNC_ATTR_NONNULL_ARG(1)
{
size_t argc = 0;
const char *p = str;
while (*p != NUL) {
const size_t len = word_length(p);
if (argv != NULL) {
// Fill the slot
argv[argc] = vim_strnsave_unquoted(p, len);
}
argc++;
p = skipwhite((p + len));
}
return argc;
}
/// Calculates the length of a shell word.
///
/// @param str A pointer to the first character of the word
/// @return The offset from `str` at which the word ends.
static size_t word_length(const char *str)
{
const char *p = str;
bool inquote = false;
size_t length = 0;
// Move `p` to the end of shell word by advancing the pointer while it's
// inside a quote or it's a non-whitespace character
while (*p && (inquote || (*p != ' ' && *p != TAB))) {
if (*p == '"') {
// Found a quote character, switch the `inquote` flag
inquote = !inquote;
} else if (*p == '\\' && inquote) {
p++;
length++;
}
p++;
length++;
}
return length;
}
/// To remain compatible with the old implementation (which forked a process
/// for writing) the entire text is copied to a temporary buffer before the
/// event loop starts. If we don't (by writing in chunks returned by `ml_get`)
/// the buffer being modified might get modified by reading from the process
/// before we finish writing.
static void read_input(StringBuilder *buf)
{
size_t written = 0;
size_t len = 0;
linenr_T lnum = curbuf->b_op_start.lnum;
char *lp = ml_get(lnum);
while (true) {
size_t l = strlen(lp + written);
if (l == 0) {
len = 0;
} else if (lp[written] == NL) {
// NL -> NUL translation
len = 1;
kv_push(*buf, NUL);
} else {
char *s = vim_strchr(lp + written, NL);
len = s == NULL ? l : (size_t)(s - (lp + written));
kv_concat_len(*buf, lp + written, len);
}
if (len == l) {
// Finished a line, add a NL, unless this line should not have one.
if (lnum != curbuf->b_op_end.lnum
|| (!curbuf->b_p_bin && curbuf->b_p_fixeol)
|| (lnum != curbuf->b_no_eol_lnum
&& (lnum != curbuf->b_ml.ml_line_count || curbuf->b_p_eol))) {
kv_push(*buf, NL);
}
lnum++;
if (lnum > curbuf->b_op_end.lnum) {
break;
}
lp = ml_get(lnum);
written = 0;
} else if (len > 0) {
written += len;
}
}
}
static size_t write_output(char *output, size_t remaining, bool eof)
{
if (!output) {
return 0;
}
char *start = output;
size_t off = 0;
while (off < remaining) {
if (output[off] == NL) {
// Insert the line
output[off] = NUL;
ml_append(curwin->w_cursor.lnum++, output, (int)off + 1,
false);
size_t skip = off + 1;
output += skip;
remaining -= skip;
off = 0;
continue;
}
if (output[off] == NUL) {
// Translate NUL to NL
output[off] = NL;
}
off++;
}
if (eof) {
if (remaining) {
// append unfinished line
ml_append(curwin->w_cursor.lnum++, output, 0, false);
// remember that the NL was missing
curbuf->b_no_eol_lnum = curwin->w_cursor.lnum;
output += remaining;
} else {
curbuf->b_no_eol_lnum = 0;
}
}
ui_flush();
return (size_t)(output - start);
}
static void shell_write_cb(Stream *stream, void *data, int status)
{
if (status) {
// Can happen if system() tries to send input to a shell command that was
// backgrounded (:call system("cat - &", "foo")). #3529 #5241
msg_schedule_semsg(_("E5677: Error writing input to shell-command: %s"),
uv_err_name(status));
}
stream_close(stream, NULL, NULL, false);
}
/// Applies 'shellxescape' (p_sxe) and 'shellxquote' (p_sxq) to a command.
///
/// @param cmd Command string
/// @return Escaped/quoted command string (allocated).
static char *shell_xescape_xquote(const char *cmd)
FUNC_ATTR_NONNULL_ALL FUNC_ATTR_MALLOC FUNC_ATTR_WARN_UNUSED_RESULT
{
if (*p_sxq == NUL) {
return xstrdup(cmd);
}
const char *ecmd = cmd;
if (*p_sxe != NUL && strcmp(p_sxq, "(") == 0) {
ecmd = vim_strsave_escaped_ext(cmd, p_sxe, '^', false);
}
size_t ncmd_size = strlen(ecmd) + strlen(p_sxq) * 2 + 1;
char *ncmd = xmalloc(ncmd_size);
// When 'shellxquote' is ( append ).
// When 'shellxquote' is "( append )".
if (strcmp(p_sxq, "(") == 0) {
vim_snprintf(ncmd, ncmd_size, "(%s)", ecmd);
} else if (strcmp(p_sxq, "\"(") == 0) {
vim_snprintf(ncmd, ncmd_size, "\"(%s)\"", ecmd);
} else {
vim_snprintf(ncmd, ncmd_size, "%s%s%s", p_sxq, ecmd, p_sxq);
}
if (ecmd != cmd) {
xfree((void *)ecmd);
}
return ncmd;
}