diff --git a/doc/user-guide b/doc/user-guide
index 1121ba26..cb3eb11c 100644
--- a/doc/user-guide
+++ b/doc/user-guide
@@ -203,6 +203,7 @@ Sortix comes with a number of home-made programs. Here is an overview:
* `mv` - move a file
* `pager` - display file page by page
* `ps` - report a snapshot of the current processes
+* `pstree` - display a tree of processes
* `pwd` - print current directory path
* `realpath` - canonicalize filesystem paths
* `regress` - run system tests
diff --git a/utils/.gitignore b/utils/.gitignore
index 5041ce50..90306a79 100644
--- a/utils/.gitignore
+++ b/utils/.gitignore
@@ -30,6 +30,7 @@ mktemp
mv
pager
ps
+pstree
pwd
realpath
rm
diff --git a/utils/Makefile b/utils/Makefile
index e943f23b..f9007d81 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -42,6 +42,7 @@ mktemp \
mv \
pager \
ps \
+pstree \
pwd \
realpath \
rm \
diff --git a/utils/pstree.cpp b/utils/pstree.cpp
new file mode 100644
index 00000000..1fd3a12a
--- /dev/null
+++ b/utils/pstree.cpp
@@ -0,0 +1,197 @@
+/*******************************************************************************
+
+ Copyright(C) Jonas 'Sortie' Termansen 2015.
+
+ This program is free software: you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by the Free
+ Software Foundation, either version 3 of the License, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ more details.
+
+ You should have received a copy of the GNU General Public License along with
+ this program. If not, see .
+
+ pstree.cpp
+ Lists processes in a nice tree.
+
+*******************************************************************************/
+
+#include
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+const char* last_basename(const char* path)
+{
+ const char* result = path;
+ for ( size_t i = 0; path[i]; i++ )
+ if ( path[i] == '/' && path[i + 1] != '/' && path[i + 1] )
+ result = path + i + 1;
+ return result;
+}
+
+static char* get_program_path_of_pid(pid_t pid)
+{
+ struct psctl_program_path ctl;
+ memset(&ctl, 0, sizeof(ctl));
+ ctl.buffer = NULL;
+ ctl.size = 0;
+ if ( psctl(pid, PSCTL_PROGRAM_PATH, &ctl) < 0 )
+ return NULL;
+ while ( true )
+ {
+ char* new_buffer = (char*) realloc(ctl.buffer, ctl.size);
+ if ( !new_buffer )
+ return free(ctl.buffer), (char*) NULL;
+ ctl.buffer = new_buffer;
+ if ( psctl(pid, PSCTL_PROGRAM_PATH, &ctl) == 0 )
+ return ctl.buffer;
+ if ( errno != ERANGE )
+ return free(ctl.buffer), (char*) NULL;
+ }
+}
+
+static void pstree(pid_t pid, const char* prefix, bool continuation)
+{
+ while ( pid != -1 )
+ {
+ struct psctl_stat psst;
+ if ( psctl(pid, PSCTL_STAT, &psst) < 0 )
+ {
+ if ( errno != ESRCH )
+ warn("psctl: PSCTL_STAT: [%" PRIiPID "]", pid);
+ return;
+ }
+ char* path_string = get_program_path_of_pid(pid);
+ const char* path = last_basename(path_string ? path_string : "");
+ if ( !continuation )
+ fputs(prefix, stdout);
+ if ( prefix[0] )
+ {
+ if ( continuation )
+ fputs("─", stdout);
+ else
+ fputs(" ", stdout);
+ if ( continuation )
+ fputs(psst.ppid_next == -1 ? "─" : "┬", stdout);
+ else
+ fputs(psst.ppid_next == -1 ? "└" : "│", stdout);
+ fputs("─", stdout);
+ }
+ printf("%s", path);
+ if ( psst.ppid_first != -1 )
+ {
+ size_t path_length = strlen(path);
+ char* new_prefix;
+ if ( prefix[0] )
+ {
+ size_t prefix_length = strlen(prefix);
+ size_t new_prefix_length = prefix_length + 3 + path_length;
+ if ( !(new_prefix = (char*) malloc(new_prefix_length + 1)) )
+ err(1, "malloc");
+ memcpy(new_prefix, prefix, prefix_length);
+ memcpy(new_prefix + prefix_length,
+ psst.ppid_next != -1 ? " | " : " ", 3);
+ for ( size_t i = 0; i < path_length; i++ )
+ new_prefix[prefix_length + 3 + i] = ' ';
+ new_prefix[prefix_length + 3 + path_length] = '\0';
+ }
+ else
+ {
+ if ( !(new_prefix = (char*) malloc(path_length + 1)) )
+ err(1, "malloc");
+ for ( size_t i = 0; i < path_length; i++ )
+ new_prefix[i] = ' ';
+ new_prefix[path_length] = '\0';
+ }
+ pstree(psst.ppid_first, new_prefix, true);
+ free(new_prefix);
+ }
+ else
+ printf("\n");
+ free(path_string);
+ continuation = false;
+ pid = psst.ppid_next;
+ }
+}
+
+static void compact_arguments(int* argc, char*** argv)
+{
+ for ( int i = 0; i < *argc; i++ )
+ {
+ while ( i < *argc && !(*argv)[i] )
+ {
+ for ( int n = i; n < *argc; n++ )
+ (*argv)[n] = (*argv)[n+1];
+ (*argc)--;
+ }
+ }
+}
+
+static void help(FILE* fp, const char* argv0)
+{
+ fprintf(fp, "Usage: %s [OPTION]...\n", argv0);
+ fprintf(fp, "List processes.\n");
+}
+
+static void version(FILE* fp, const char* argv0)
+{
+ fprintf(fp, "%s (Sortix) %s\n", argv0, VERSIONSTR);
+ fprintf(fp, "License GPLv3+: GNU GPL version 3 or later .\n");
+ fprintf(fp, "This is free software: you are free to change and redistribute it.\n");
+ fprintf(fp, "There is NO WARRANTY, to the extent permitted by law.\n");
+}
+
+int main(int argc, char* argv[])
+{
+ setlocale(LC_ALL, "");
+
+ const char* argv0 = argv[0];
+ for ( int i = 1; i < argc; i++ )
+ {
+ const char* arg = argv[i];
+ if ( arg[0] != '-' || !arg[1] )
+ continue;
+ argv[i] = NULL;
+ if ( !strcmp(arg, "--") )
+ break;
+ if ( arg[1] != '-' )
+ {
+ while ( char c = *++arg ) switch ( c )
+ {
+ default:
+ fprintf(stderr, "%s: unknown option -- '%c'\n", argv0, c);
+ help(stderr, argv0);
+ exit(1);
+ }
+ }
+ else if ( !strcmp(arg, "--help") )
+ help(stdout, argv0), exit(0);
+ else if ( !strcmp(arg, "--version") )
+ version(stdout, argv0), exit(0);
+ else
+ {
+ fprintf(stderr, "%s: unknown option: %s\n", argv0, arg);
+ help(stderr, argv0);
+ exit(1);
+ }
+ }
+
+ compact_arguments(&argc, &argv);
+
+ if ( 1 < argc )
+ err(1, "extra operand: %s", argv[1]);
+
+ pstree(1, "", true);
+
+ return ferror(stdout) || fflush(stdout) == EOF ? 1 : 0;
+}