fixes: improve login environment handling (#114)

* chore(organization): allow nested header and c files

* feat: add shell login "middleware" & etc:
  * lidm now calls `bash` (or other shells, depends on PACKAGE cfg) in
  login mode as a session wrapper to source most env (can be disabled)
  * this fixes a lot of env problems with all `/etc/profile` and more

Extra:
* implemented a musl compatible version of `execvpe` and now lidm should
  search for PATH everywhere it needs to
* `search_path` now also checks if the found binary is properly
  executable
* lidm now uses `confstr` for a decent PATH default if none is found
* logs are unbuffered for cases where debug logs appear empty (exit
  without handlers moment)

* chore: one-time evaluate certain makefile vars

---------

Co-authored-by: grialion <48643945+grialion@users.noreply.github.com>

src/auth.c

@@ -1,10 +1,11 @@
-// TODO: handle `fork() == -1`// TODO: handle `fork() == -1`s
+// TODO: handle `fork() == -1`
 
 #include <errno.h>
 #include <grp.h>
 #include <pwd.h>
 #include <security/pam_misc.h>
 #include <signal.h>
+#include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -21,7 +22,8 @@
 #include "pam.h"
 #include "sessions.h"
 #include "ui.h"
-#include "util.h"
+#include "util/path.h"
+#include "util/vec.h"
 
 #define XORG_MESSAGE_LENGTH 16
 
@@ -80,16 +82,6 @@ static void source_paths(struct Vector* NNULLABLE vec_envlist,
   }
 }
 
-/*char *buf;*/
-/*size_t bsize = snprintf(NULL, 0, "/run/user/%d", pw->pw_uid) + 1;*/
-/*buf = malloc(bsize);*/
-/*snprintf(buf, bsize, "/run/user/%d", pw->pw_uid);*/
-/*setenv("XDG_RUNTIME_DIR", buf, true);*/
-/*setenv("XDG_SESSION_CLASS", "user", true);*/
-/*setenv("XDG_SESSION_ID", "1", true);*/
-/*setenv("XDG_SESSION_DESKTOP", , true);*/
-/*setenv("XDG_SEAT", "seat0", true);*/
-
 struct child_msg {
   char* msg;
   int _errno;
@@ -176,7 +168,8 @@ static void start_xorg_server(struct passwd* pw, char** NNULLABLE envlist,
 
 // TODO: add error msgs
 /// returns on completion
-static void launch_with_xorg_server(struct session_exec* NNULLABLE exec,
+static void launch_with_xorg_server(struct config* config,
+                                    struct session_exec* NNULLABLE exec,
                                     struct passwd* pw,
                                     char** NNULLABLE envlist) {
   int xorg_pipefd[2];
@@ -212,10 +205,14 @@ static void launch_with_xorg_server(struct session_exec* NNULLABLE exec,
   (void)fflush(NULL);
   pid_t xorg_session_pid = fork();
   if (xorg_session_pid == 0) {
-    int exit = session_exec_exec(exec, envlist);
-    perror("exec error");
+    if (config->behavior.bypass_shell_login)
+      session_exec_exec(exec, envlist);
+    else
+      session_exec_login_through_shell(exec, envlist);
+
+    perror("session exec error");
     (void)fputs("failure calling session\n", stderr);
-    _exit(exit);
+    _exit(EXIT_FAILURE);
   }
 
   // looks weird, waiting on -1 should wait on any child and then just check if
@@ -254,8 +251,8 @@ static void launch_with_xorg_server(struct session_exec* NNULLABLE exec,
     char _dummy;                              \
     read(pipefd[0], &_dummy, sizeof(_dummy)); \
   }
-inline static void forked(int pipefd[2], struct passwd* pw,
-                          char* NNULLABLE user,
+inline static void forked(struct config* config, int pipefd[2],
+                          struct passwd* pw, char* NNULLABLE user,
                           struct session* NNULLABLE session,
                           char** NNULLABLE envlist) {
   if (chdir(pw->pw_dir) == -1) SEND_ERR("chdir");
@@ -267,14 +264,26 @@ inline static void forked(int pipefd[2], struct passwd* pw,
   DUMMY_READ();
   close(pipefd[0]);
 
+  if (!getenv("PATH")) {
+    size_t path_size = confstr(_CS_PATH, NULL, 0);
+    char* path_env = malloc(path_size);
+    confstr(_CS_PATH, path_env, path_size);
+    setenv("PATH", path_env, 1);
+    free(path_env);
+  }
+
+  log_printf(" [I] using shell login?: %s",
+             config->behavior.bypass_shell_login ? "true" : "false");
   if (session->type == XORG) {
-    launch_with_xorg_server(&session->exec, pw, envlist);
+    launch_with_xorg_server(config, &session->exec, pw, envlist);
     _exit(EXIT_SUCCESS);
   } else {
-    int exit = session_exec_exec(&session->exec, envlist);
-    perror("exec error");
-    (void)fputs("failure calling session\n", stderr);
-    _exit(exit);
+    if (config->behavior.bypass_shell_login)
+      session_exec_exec(&session->exec, envlist);
+    else
+      session_exec_login_through_shell(&session->exec, envlist);
+    perror("session exec error");
+    _exit(EXIT_FAILURE);
   }
 }
 #undef SEND_MSG
@@ -325,7 +334,7 @@ bool launch(char* user, char* passwd, struct session session, void (*cb)(void),
 
   uint pid = fork();
   if (pid == 0)
-    forked(pipefd, pw, user, &session, envlist);
+    forked(config, pipefd, pw, user, &session, envlist);
   else {
     struct child_msg msg;
     read(pipefd[0], &msg, sizeof(struct child_msg));

src/config.c

@@ -11,14 +11,15 @@
 
 #include "config.h"
 #include "desktop.h"
+#include "keys.h"
 #include "log.h"
 #include "macros.h"
-#include "util.h"
+#include "util/vec.h"
 
 #define UPPER_HALF_BYTE 4
 int parse_hex(char* _at, char x1, char x2) {
   // make linter happy
-  u_char* at = (u_char*)_at;
+  uint8_t* at = (uint8_t*)_at;
 
   *at = 0;
 

src/desktop_exec.c

@@ -9,61 +9,39 @@
 
 #include "desktop_exec.h"
 #include "macros.h"
+#include "util/path.h"
 
 // constants for exec string parsing
 #define MAX_ARGS 100
 // ARG_LENGTH is the initial length of a parsed argument
 #define ARG_LENGTH 64
 
-// returns NULL on any error
-// otherwise it returns the absolute path of the program that MUST BE FREED
-char* NULLABLE search_path(const char* NNULLABLE for_binary) {
-  if (strchr(for_binary, '/') != NULL) {
-    // skip absolute paths
-    return strdup(for_binary);
+char* NULLABLE desktop_as_cmdline(char** args) {
+  if (args[0] == NULL) return NULL;
+  size_t fmtd_len = 0;
+
+  char** ptr = args;
+  while (*ptr) {
+    fmtd_len += strlen(*ptr) + 1;
+    ptr++;
   }
-  char* path_env = getenv("PATH");
-  if (!path_env) return NULL;
-  char* path = strdup(path_env);
-  if (!path) return NULL;
+  fmtd_len -= 1;
 
-  char* tok = strtok(path, ":");
-  while (tok) {
-    char* bin_path;
-    asprintf(&bin_path, "%s/%s", tok, for_binary);
-    if (!bin_path) {
-      free(path);
-      return NULL;
-    }
+  char* fmt_cmdline = malloc(fmtd_len + 1);
+  if (!fmt_cmdline) return NULL;
 
-    struct stat stat_buf;
-    if (stat(bin_path, &stat_buf) == 0) {
-      // TODO: check exec bit ig
-      // if(stat_buf.) {}
-      free(path);
-      return bin_path;
-    }
+  size_t fmting_len = 0;
+  ptr = args;
+  while (*ptr) {
+    char* nbyte = stpcpy(&fmt_cmdline[fmting_len], *ptr);
+    *nbyte = ' ';
 
-    free(bin_path);
-    tok = strtok(NULL, ":");
+    fmting_len += nbyte - &fmt_cmdline[fmting_len] + 1;
+    ptr++;
   }
+  fmt_cmdline[fmting_len - 1] = '\0';
 
-  free(path);
-  return NULL;
-}
-
-// returns -1 on exec failure and -2 on search failure
-int execvpe_desktop(char** args, char* NNULLABLE* NNULLABLE envlist) {
-  char* new_arg = search_path(args[0]);
-  if (!new_arg) return -2;
-
-  free(args[0]);
-  args[0] = new_arg;
-
-  int status = execve(args[0], args, envlist);
-  free(new_arg);
-
-  return status;
+  return fmt_cmdline;
 }
 
 // parse Exec=/bin/prog arg1 arg2\ with\ spaces

src/efield.c

@@ -2,7 +2,7 @@
 
 #include "efield.h"
 #include "ui.h"
-#include "util.h"
+#include "util/utf8.h"
 
 struct editable_field efield_new(char* content) {
   struct editable_field efield;
@@ -16,14 +16,14 @@ struct editable_field efield_new(char* content) {
   return efield;
 }
 
-void efield_trim(struct editable_field* self, u_char pos) {
+void efield_trim(struct editable_field* self, uint8_t pos) {
   self->pos = pos;
   self->content[pos + 1] = '\0';
 }
 
 #define BACKSPACE_CODE 127
 void efield_update(struct editable_field* self, char* update) {
-  u_char insert_len = strlen(update);
+  uint8_t insert_len = strlen(update);
   if (insert_len == 0) return;
 
   if (self->pos > strlen(self->content))
@@ -61,7 +61,7 @@ bool efield_seek(struct editable_field* self, char seek) {
   if (*self->content == '\0') return false;
   if (seek == 0) return false;
 
-  u_char count = seek < 0 ? -seek : seek;
+  uint8_t count = seek < 0 ? -seek : seek;
   char* ptr = &self->content[self->pos];
   char* start = ptr;
 
@@ -75,6 +75,6 @@ bool efield_seek(struct editable_field* self, char seek) {
     }
   }
 
-  self->pos = (u_char)(ptr - self->content);
+  self->pos = (uint8_t)(ptr - self->content);
   return ptr != start;
 }

src/keys.c

@@ -0,0 +1,77 @@
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "keys.h"
+#include "macros.h"
+#include "ui.h"
+
+static int selret_magic();
+
+int find_keyname(enum Keys* at, const char* name) {
+  for (size_t i = 0; i < LEN(KEY_MAPPINGS); i++) {
+    if (strcmp(KEY_NAMES[i], name) == 0) {
+      *at = (enum Keys)i;
+      return 0;
+    }
+  }
+
+  return -1;
+}
+
+struct option_keys find_ansi(const char* seq) {
+  for (size_t i = 0; i < LEN(KEY_MAPPINGS); i++) {
+    struct key_mapping mapping = KEY_MAPPINGS[i];
+    for (size_t j = 0; mapping.sequences[j] != NULL; j++) {
+      if (strcmp(mapping.sequences[j], seq) == 0) {
+        return (struct option_keys){
+            .is_some = true,
+            .key = (enum Keys)i,
+        };
+      }
+    }
+  }
+  return (struct option_keys){.is_some = false};
+}
+
+void read_press(uint8_t* length, char* out) {
+  *length = 0;
+
+  while (true) {
+    if (read(STDIN_FILENO, &out[(*length)++], 1) != 1) {
+      print_errno("read error");
+      sleep(3);
+      exit(1);
+    }
+    int selret = selret_magic();
+    if (selret == -1) {
+      print_errno("selret error");
+    } else if (selret != 1) {
+      out[*length] = '\0';
+      return;
+    }
+  }
+}
+
+bool read_press_nb(uint8_t* length, char* out, struct timeval* tv) {
+  fd_set fds;
+  FD_ZERO(&fds);
+  FD_SET(STDIN_FILENO, &fds);
+  errno = 0;
+  int ret = select(STDIN_FILENO + 1, &fds, NULL, NULL, tv);
+  if (errno || ret <= 0) return false;
+
+  read_press(length, out);
+  return true;
+}
+
+// https://stackoverflow.com/a/48040042
+static int selret_magic() {
+  fd_set set;
+  struct timeval timeout;
+  FD_ZERO(&set);
+  FD_SET(STDIN_FILENO, &set);
+  timeout.tv_sec = 0;
+  timeout.tv_usec = 0;
+  return select(1, &set, NULL, NULL, &timeout);
+}

src/log.c

@@ -8,6 +8,7 @@ static FILE* logger_out = NULL;
 
 void log_init(FILE* fd) {
   if (logger_out) (void)fclose(logger_out);
+  (void)setvbuf(fd, NULL, _IONBF, 0);
   logger_out = fd;
 }
 

src/main.c

@@ -15,7 +15,7 @@
 #include "signal_handler.h"
 #include "ui.h"
 #include "users.h"
-#include "util.h"
+#include "util/vec.h"
 
 #define DATESTR_MAXBUFSIZE 0x20
 
@@ -31,6 +31,7 @@ int main(int argc, char* argv[]) {
     }
 
     log_init(log_fd);
+    log_puts("Starting log:");
   }
 
   if (argc == 2) {

src/ofield.c

@@ -1,10 +1,9 @@
 #include <stddef.h>
 
-#include "config.h"
 #include "efield.h"
 #include "ofield.h"
 #include "ui.h"
-#include "util.h"
+#include "util/utf8.h"
 
 struct opts_field ofield_new(size_t opts) {
   if (opts == 0) {
@@ -55,11 +54,11 @@ bool ofield_seek(struct opts_field* self, char seek) {
   return true;
 }
 
-u_char ofield_display_cursor_col(struct opts_field* self, u_char maxlen) {
+uint8_t ofield_display_cursor_col(struct opts_field* self, uint8_t maxlen) {
   if (self->current_opt == 0) {
-    u_char display_len = utf8len(self->efield.content);
-    u_char pos = utf8len_until(self->efield.content,
-                               &self->efield.content[self->efield.pos]);
+    uint8_t display_len = utf8len(self->efield.content);
+    uint8_t pos = utf8len_until(self->efield.content,
+                                &self->efield.content[self->efield.pos]);
 
     if (display_len > maxlen) {
       if (pos < maxlen / 2) {

src/pam.c

@@ -6,6 +6,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "log.h"
 #include "macros.h"
 #include "pam.h"
 #include "sessions.h"
@@ -92,6 +93,10 @@ struct pamh_getenv_status pamh_get_complete_env(pam_handle_t* handle,
   char** raw_envlist = pam_getenvlist(handle);
   if (!raw_envlist) FAIL(PAMH_ERR_ERRNO, "pam_getenvlist");
 
+  char** ptr = raw_envlist;
+  while (*ptr)
+    log_printf("[I] got pam env %s\n", *(ptr++));
+
   struct envpair extra_env[] = {
       {"TERM", getenv("TERM")},
       {"PATH", getenv("PATH")},

src/sessions.c

@@ -1,3 +1,4 @@
+#include <errno.h>
 #include <ftw.h>
 #include <limits.h>
 #include <stdbool.h>
@@ -6,13 +7,16 @@
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <unistd.h>
 
+#include "config.h"
 #include "desktop.h"
 #include "desktop_exec.h"
 #include "log.h"
 #include "macros.h"
 #include "sessions.h"
-#include "util.h"
+#include "util/path.h"
+#include "util/vec.h"
 
 struct source_dir {
   enum SessionType type;
@@ -163,3 +167,54 @@ struct Vector get_avaliable_sessions() {
 
   return sessions;
 }
+
+int session_exec_exec(struct session_exec* NNULLABLE exec,
+                      char* NULLABLE* NNULLABLE envp) {
+  switch (exec->typ) {
+    case EXEC_SHELL: {
+      char* argv[] = {exec->shell, NULL};
+      return execvpe(exec->shell, argv, envp);
+    }
+    case EXEC_DESKTOP:
+      return execvpe(exec->desktop.args[0], exec->desktop.args, envp);
+    default:
+      __builtin_unreachable();
+  }
+}
+
+/// So the reason this doesn't use the user shell is because that can really be
+/// anything, also assuming it were fish for example, it can't execute posix
+/// shell files and that leaves it out of most `/etc/profile.d/` scripts.
+///
+/// I'll just default to bash for now as it's able to source almost everything
+/// and takes most flags. Maybe will try to make this more sophisticated in the
+/// future.
+///
+/// This respects errno. Even also works as any exec family function.
+#ifndef LOGIN_SHELL
+  #define LOGIN_SHELL "bash"
+#endif
+// This triggers login behavior
+#define LOGIN_SHELL_ARG0 "-" LOGIN_SHELL
+int session_exec_login_through_shell(struct session_exec* NNULLABLE exec,
+                                     char* NULLABLE* NNULLABLE envp) {
+  switch (exec->typ) {
+    case EXEC_SHELL: {
+      char* argv[] = {LOGIN_SHELL_ARG0, "-c", exec->shell, NULL};
+      return execvpe(LOGIN_SHELL, argv, envp);
+    }
+    case EXEC_DESKTOP: {
+      char* name = desktop_as_cmdline(exec->desktop.args);
+      if (!name) {
+        errno = EINVAL;
+        return -1;
+      }
+      char* argv[] = {LOGIN_SHELL_ARG0, "-c", name, NULL};
+      int ret = execvpe(LOGIN_SHELL, argv, envp);
+      free(name);
+      return ret;
+    }
+    default:
+      __builtin_unreachable();
+  }
+}

src/ui.c

@@ -32,9 +32,9 @@
 #include "ui.h"
 #include "ui_state.h"
 #include "users.h"
-#include "util.h"
+#include "util/utf8.h"
 
-const u_char INPUTS_N = 3;
+const uint8_t INPUTS_N = 3;
 
 struct uint_point {
   uint x;
@@ -135,11 +135,11 @@ char* trunc_gethostname(size_t maxlen, const char* const ELLIPSIS) {
 }
 
 void ui_update_cursor_focus() {
-  u_char line = box_start.y;
-  u_char col = box_start.x + VALUES_COL;
+  uint8_t line = box_start.y;
+  uint8_t col = box_start.x + VALUES_COL;
 
   struct opts_field* ofield = get_opts_ffield();
-  u_char maxlen = VALUE_MAXLEN;
+  uint8_t maxlen = VALUE_MAXLEN;
   if (ofield->opts > 1) {
     maxlen -= utf8len(g_config->strings.opts_pre) +
               utf8len(g_config->strings.opts_post);
@@ -269,7 +269,7 @@ int load(struct Vector* users, struct Vector* sessions) {
   scratch_print_ui();
 
   /// INTERACTIVE
-  u_char len;
+  uint8_t len;
   char seq[0xff];
   uint esc = 0;
   while (true) {
@@ -362,11 +362,11 @@ void clean_line(struct uint_point origin, uint line) {
   printf("\x1b[%d;%dH%s", origin.y + line, origin.x + 1, line_cleaner);
 }
 
-u_char get_render_pos_offset(struct opts_field* self, u_char maxlen) {
+uint8_t get_render_pos_offset(struct opts_field* self, uint8_t maxlen) {
   if (self->current_opt != 0) return 0;
 
-  u_char pos = utf8len_until(self->efield.content,
-                             &self->efield.content[self->efield.pos]);
+  uint8_t pos = utf8len_until(self->efield.content,
+                              &self->efield.content[self->efield.pos]);
   return pos - ofield_display_cursor_col(self, maxlen);
 }
 
@@ -439,8 +439,8 @@ void print_session(struct session session, bool multiple) {
 
   char* toprint = session.name;
   if (multiple) {
-    u_char maxlen = VALUE_MAXLEN - utf8len(g_config->strings.opts_pre) -
-                    utf8len(g_config->strings.opts_post);
+    uint8_t maxlen = VALUE_MAXLEN - utf8len(g_config->strings.opts_pre) -
+                     utf8len(g_config->strings.opts_post);
     toprint += get_render_pos_offset(&of_session, maxlen);
     size_t printlen = utf8seekn(toprint, maxlen) - toprint;
 
@@ -467,8 +467,8 @@ void print_user(struct user user, bool multiple) {
 
   char* toprint = user.display_name;
   if (multiple) {
-    u_char maxlen = VALUE_MAXLEN - utf8len(g_config->strings.opts_pre) -
-                    utf8len(g_config->strings.opts_post);
+    uint8_t maxlen = VALUE_MAXLEN - utf8len(g_config->strings.opts_pre) -
+                     utf8len(g_config->strings.opts_post);
     toprint += get_render_pos_offset(&of_session, maxlen);
     size_t printlen = utf8seekn(toprint, maxlen) - toprint;
 

src/users.c

@@ -7,7 +7,7 @@
 #include "log.h"
 #include "macros.h"
 #include "users.h"
-#include "util.h"
+#include "util/vec.h"
 
 // NOLINTNEXTLINE(readability-identifier-length)
 int build_user(struct user* NNULLABLE user, struct passwd* p) {

src/util.c

@@ -1,238 +0,0 @@
-#include <asm-generic/errno-base.h>
-#include <errno.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#include "keys.h"
-#include "ui.h"
-#include "util.h"
-
-static int selret_magic();
-
-int find_keyname(enum Keys* at, const char* name) {
-  for (size_t i = 0; i < LEN(KEY_MAPPINGS); i++) {
-    if (strcmp(KEY_NAMES[i], name) == 0) {
-      *at = (enum Keys)i;
-      return 0;
-    }
-  }
-
-  return -1;
-}
-
-struct option_keys find_ansi(const char* seq) {
-  for (size_t i = 0; i < LEN(KEY_MAPPINGS); i++) {
-    struct key_mapping mapping = KEY_MAPPINGS[i];
-    for (size_t j = 0; mapping.sequences[j] != NULL; j++) {
-      if (strcmp(mapping.sequences[j], seq) == 0) {
-        return (struct option_keys){
-            .is_some = true,
-            .key = (enum Keys)i,
-        };
-      }
-    }
-  }
-  return (struct option_keys){.is_some = false};
-}
-
-void read_press(u_char* length, char* out) {
-  *length = 0;
-
-  while (true) {
-    if (read(STDIN_FILENO, &out[(*length)++], 1) != 1) {
-      print_errno("read error");
-      sleep(3);
-      exit(1);
-    }
-    int selret = selret_magic();
-    if (selret == -1) {
-      print_errno("selret error");
-    } else if (selret != 1) {
-      out[*length] = '\0';
-      return;
-    }
-  }
-}
-
-bool read_press_nb(u_char* length, char* out, struct timeval* tv) {
-  fd_set fds;
-  FD_ZERO(&fds);
-  FD_SET(STDIN_FILENO, &fds);
-  errno = 0;
-  int ret = select(STDIN_FILENO + 1, &fds, NULL, NULL, tv);
-  if (errno || ret <= 0) return false;
-
-  read_press(length, out);
-  return true;
-}
-
-// https://stackoverflow.com/a/48040042
-static int selret_magic() {
-  fd_set set;
-  struct timeval timeout;
-  FD_ZERO(&set);
-  FD_SET(STDIN_FILENO, &set);
-  timeout.tv_sec = 0;
-  timeout.tv_usec = 0;
-  return select(1, &set, NULL, NULL, &timeout);
-}
-
-// UTF-8 shii
-#define UTF8_CONT_MSK 0b11000000
-#define UTF8_CONT_VAL 0b10000000
-bool utf8_iscont(char byte) {
-  return (byte & UTF8_CONT_MSK) == UTF8_CONT_VAL;
-}
-
-size_t utf8len(const char* str) {
-  size_t len = 0;
-  while (*str != '\0') {
-    if (!utf8_iscont(*(str++))) len++;
-  }
-
-  return len;
-}
-
-size_t utf8len_until(const char* str, const char* until) {
-  size_t len = 0;
-  while (str < until) {
-    if (!utf8_iscont(*(str++))) len++;
-  }
-
-  return len;
-}
-
-size_t utf8trunc(char* str, size_t n) {
-  size_t bytes = 0;
-  while (true) {
-    if (str[bytes] == '\0') break;
-    if (utf8_iscont(str[bytes])) {
-      bytes++;
-      continue;
-    }
-    if (n == 0) {
-      str[bytes] = '\0';
-      break;
-    }
-    bytes++;
-    n--;
-  }
-  return bytes;
-}
-
-const char* utf8back(const char* str) {
-  while (utf8_iscont(*(--str))) {
-  }
-  return str;
-}
-const char* utf8seek(const char* str) {
-  while (utf8_iscont(*(++str))) {
-  }
-  return str;
-}
-
-const char* utf8seekn(const char* str, size_t n) {
-  while (n > 0 && *str != '\0') {
-    str = utf8seek(str);
-    n--;
-  }
-  return str;
-}
-
-// Vector shii
-const struct Vector VEC_NEW = {
-    .length = 0,
-    .capacity = 0,
-    .pages = NULL,
-};
-
-struct Vector vec_from_raw(void** raw) {
-  size_t len = 0;
-  while (raw[len])
-    len++;
-
-  return (struct Vector){
-      .length = len,
-      .capacity = len,
-      .pages = raw,
-  };
-}
-
-void** vec_as_raw(struct Vector self) {
-  if (vec_push(&self, NULL) != 0) return NULL;
-  return self.pages;
-}
-
-int vec_resize(struct Vector* self, size_t size) {
-  void** new_location =
-      (void**)realloc((void*)self->pages, size * sizeof(void*));
-  if (new_location != NULL) {
-    if (self->length > size) self->length = size;
-    self->capacity = size;
-    self->pages = new_location;
-  } else {
-    return -1;
-  }
-  return 0;
-}
-
-int vec_reserve(struct Vector* self, size_t size) {
-  uint32_t new_capacity = self->capacity;
-  while (self->length + size > new_capacity) {
-    new_capacity = new_capacity + (new_capacity >> 1) +
-                   1; // cap * 1.5 + 1; 0 1 2 4 7 11...
-  }
-  return vec_resize(self, new_capacity);
-}
-
-int vec_reserve_exact(struct Vector* self, size_t size) {
-  uint32_t needed_capacity = self->length + size;
-  if (self->capacity < needed_capacity) {
-    return vec_resize(self, needed_capacity);
-  }
-  return 0;
-}
-
-int vec_push(struct Vector* self, void* item) {
-  int res_ret = vec_reserve(self, 1);
-  if (res_ret != 0) return res_ret;
-
-  self->pages[self->length++] = item;
-  return 0;
-}
-
-void vec_free(struct Vector* self) {
-  while (self->length > 0)
-    free(self->pages[--self->length]);
-
-  vec_clear(self);
-}
-
-void vec_clear(struct Vector* self) {
-  free((void*)self->pages);
-  vec_reset(self);
-}
-
-void vec_reset(struct Vector* self) {
-  *self = (struct Vector){
-      .length = 0,
-      .capacity = 0,
-      .pages = NULL,
-  };
-}
-
-void* vec_pop(struct Vector* self) {
-  if (self->length == 0) return NULL;
-
-  return self->pages[--self->length];
-}
-
-void* vec_get(struct Vector* self, size_t index) {
-  if (index >= self->length) return NULL;
-
-  return self->pages[index];
-}

src/util/path.c

@@ -0,0 +1,64 @@
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "util/path.h"
+
+// returns NULL on any error
+// otherwise it returns the absolute path of the program that MUST BE FREED
+//
+// Should be almost completely posix compliant, except it won't resolve empty
+// PATH entries relative to the cwd
+char* NULLABLE search_path(const char* NNULLABLE for_binary) {
+  if (strchr(for_binary, '/') != NULL) {
+    // skip absolute paths
+    return strdup(for_binary);
+  }
+  char* path_env = getenv("PATH");
+  if (!path_env) return NULL;
+  char* path = strdup(path_env);
+  if (!path) return NULL;
+
+  char* tok = strtok(path, ":");
+  while (tok) {
+    char* bin_path;
+    asprintf(&bin_path, "%s/%s", tok, for_binary);
+    if (!bin_path) {
+      free(path);
+      return NULL;
+    }
+
+    struct stat stat_buf;
+    if (stat(bin_path, &stat_buf) == 0 && access(bin_path, X_OK) == 0) {
+      free(path);
+      return bin_path;
+    }
+
+    free(bin_path);
+    tok = strtok(NULL, ":");
+  }
+
+  free(path);
+  return NULL;
+}
+
+// This is present in glibc ONLY with GNU extensions, this aims to provide a
+// musl compatible variant.
+//
+// Respects errno of exec functions family.
+int execvpe(const char* NNULLABLE file, char* NULLABLE const argv[NNULLABLE],
+            char* NULLABLE const envp[NNULLABLE]) {
+  char* path = search_path(file);
+  if (!path) {
+    errno = ENOENT;
+    return -1;
+  }
+  int ret = execve(path, argv, envp);
+  free(path);
+  return ret;
+}

src/util/utf8.c

@@ -0,0 +1,62 @@
+#include "util/utf8.h"
+
+#define UTF8_CONT_MSK 0b11000000
+#define UTF8_CONT_VAL 0b10000000
+bool utf8_iscont(char byte) {
+  return (byte & UTF8_CONT_MSK) == UTF8_CONT_VAL;
+}
+
+size_t utf8len(const char* str) {
+  size_t len = 0;
+  while (*str != '\0') {
+    if (!utf8_iscont(*(str++))) len++;
+  }
+
+  return len;
+}
+
+size_t utf8len_until(const char* str, const char* until) {
+  size_t len = 0;
+  while (str < until) {
+    if (!utf8_iscont(*(str++))) len++;
+  }
+
+  return len;
+}
+
+size_t utf8trunc(char* str, size_t n) {
+  size_t bytes = 0;
+  while (true) {
+    if (str[bytes] == '\0') break;
+    if (utf8_iscont(str[bytes])) {
+      bytes++;
+      continue;
+    }
+    if (n == 0) {
+      str[bytes] = '\0';
+      break;
+    }
+    bytes++;
+    n--;
+  }
+  return bytes;
+}
+
+const char* utf8back(const char* str) {
+  while (utf8_iscont(*(--str))) {
+  }
+  return str;
+}
+const char* utf8seek(const char* str) {
+  while (utf8_iscont(*(++str))) {
+  }
+  return str;
+}
+
+const char* utf8seekn(const char* str, size_t n) {
+  while (n > 0 && *str != '\0') {
+    str = utf8seek(str);
+    n--;
+  }
+  return str;
+}

src/util/vec.c

@@ -0,0 +1,96 @@
+#include <stdlib.h>
+
+#include "util/vec.h"
+
+const struct Vector VEC_NEW = {
+    .length = 0,
+    .capacity = 0,
+    .pages = NULL,
+};
+
+struct Vector vec_from_raw(void** raw) {
+  size_t len = 0;
+  while (raw[len])
+    len++;
+
+  return (struct Vector){
+      .length = len,
+      .capacity = len,
+      .pages = raw,
+  };
+}
+
+void** vec_as_raw(struct Vector self) {
+  if (vec_push(&self, NULL) != 0) return NULL;
+  return self.pages;
+}
+
+int vec_resize(struct Vector* self, size_t size) {
+  void** new_location =
+      (void**)realloc((void*)self->pages, size * sizeof(void*));
+  if (new_location != NULL) {
+    if (self->length > size) self->length = size;
+    self->capacity = size;
+    self->pages = new_location;
+  } else {
+    return -1;
+  }
+  return 0;
+}
+
+int vec_reserve(struct Vector* self, size_t size) {
+  uint32_t new_capacity = self->capacity;
+  while (self->length + size > new_capacity) {
+    new_capacity = new_capacity + (new_capacity >> 1) +
+                   1; // cap * 1.5 + 1; 0 1 2 4 7 11...
+  }
+  return vec_resize(self, new_capacity);
+}
+
+int vec_reserve_exact(struct Vector* self, size_t size) {
+  uint32_t needed_capacity = self->length + size;
+  if (self->capacity < needed_capacity) {
+    return vec_resize(self, needed_capacity);
+  }
+  return 0;
+}
+
+int vec_push(struct Vector* self, void* item) {
+  int res_ret = vec_reserve(self, 1);
+  if (res_ret != 0) return res_ret;
+
+  self->pages[self->length++] = item;
+  return 0;
+}
+
+void vec_free(struct Vector* self) {
+  while (self->length > 0)
+    free(self->pages[--self->length]);
+
+  vec_clear(self);
+}
+
+void vec_clear(struct Vector* self) {
+  free((void*)self->pages);
+  vec_reset(self);
+}
+
+void vec_reset(struct Vector* self) {
+  *self = (struct Vector){
+      .length = 0,
+      .capacity = 0,
+      .pages = NULL,
+  };
+}
+
+void* vec_pop(struct Vector* self) {
+  if (self->length == 0) return NULL;
+
+  return self->pages[--self->length];
+}
+
+void* vec_get(struct Vector* self, size_t index) {
+  if (index >= self->length) return NULL;
+
+  return self->pages[index];
+}