diff --git a/doc/user-guide b/doc/user-guide
index 68092fd3..f9247f7b 100644
--- a/doc/user-guide
+++ b/doc/user-guide
@@ -195,6 +195,7 @@ Sortix comes with a number of home-made programs. Here is an overview:
* `uptime` - time since initialization
* `wc` - count words and lines
* `which` - find path to command
+* `yes` - repeatedly output a line
Third Party Software
--------------------
diff --git a/utils/.gitignore b/utils/.gitignore
index 42ece0d8..314a0aa9 100644
--- a/utils/.gitignore
+++ b/utils/.gitignore
@@ -47,3 +47,4 @@ uptime
wc
which
xinstall
+yes
diff --git a/utils/Makefile b/utils/Makefile
index e8f9809d..4deec737 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -58,6 +58,7 @@ uniq \
uptime \
wc \
which \
+yes \
BINARIES=\
$(BINARIES_EXCEPT_INSTALL) \
diff --git a/utils/yes.cpp b/utils/yes.cpp
new file mode 100644
index 00000000..4c554165
--- /dev/null
+++ b/utils/yes.cpp
@@ -0,0 +1,108 @@
+/*******************************************************************************
+
+ Copyright(C) Jonas 'Sortie' Termansen 2014.
+
+ 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 .
+
+ yes.cpp
+ Repeatedly output a line.
+
+*******************************************************************************/
+
+#include
+#include
+#include
+
+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 [STRING]...\n", argv0);
+ fprintf(fp, " or: %s OPTION\n", argv0);
+ fprintf(fp, "Repeatedly output a line with all specified STRING(s), or 'y'.\n");
+ fprintf(fp, "\n");
+ fprintf(fp, " --help display this help and exit\n");
+ fprintf(fp, " --version output version information and exit\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[])
+{
+ 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);
+
+ while ( true )
+ {
+ if ( argc == 1 )
+ {
+ printf("y");
+ }
+ else
+ {
+ for ( int i = 1; i < argc; i++ )
+ printf("%s%s", 1 < i ? " " : "", argv[i]);
+ }
+ printf("\n");
+ }
+
+ return 0;
+}