Add nohup

6 files changed, 96 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index f9e5d40..ba180f0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,6 +16,7 @@ src/include/shh-portable-utils/config.h
 /link
 /ln
 /nice
+/nohup
 /renice
 /tee
 /true
diff --git a/package/deps.mak b/package/deps.mak
index d67c79a..09c9583 100644
--- a/package/deps.mak
+++ b/package/deps.mak
@@ -14,6 +14,7 @@ src/shh-portable-utils/false.o src/shh-portable-utils/false.lo: src/shh-portable
 src/shh-portable-utils/link.o src/shh-portable-utils/link.lo: src/shh-portable-utils/link.c
 src/shh-portable-utils/ln.o src/shh-portable-utils/ln.lo: src/shh-portable-utils/ln.c
 src/shh-portable-utils/nice.o src/shh-portable-utils/nice.lo: src/shh-portable-utils/nice.c
+src/shh-portable-utils/nohup.o src/shh-portable-utils/nohup.lo: src/shh-portable-utils/nohup.c
 src/shh-portable-utils/parse_group.o src/shh-portable-utils/parse_group.lo: src/shh-portable-utils/parse_group.c
 src/shh-portable-utils/parse_user.o src/shh-portable-utils/parse_user.lo: src/shh-portable-utils/parse_user.c src/shh-portable-utils/shhfuncs.h
 src/shh-portable-utils/renice.o src/shh-portable-utils/renice.lo: src/shh-portable-utils/renice.c src/shh-portable-utils/shhfuncs.h
@@ -46,6 +47,8 @@ ln: EXTRA_LIBS := -lskarnet
 ln: src/shh-portable-utils/ln.o
 nice: EXTRA_LIBS := -lskarnet
 nice: src/shh-portable-utils/nice.o
+nohup: EXTRA_LIBS := -lskarnet
+nohup: src/shh-portable-utils/nohup.o
 renice: EXTRA_LIBS := -lskarnet
 renice: src/shh-portable-utils/renice.o src/shh-portable-utils/parse_user.o
 tee: EXTRA_LIBS := -lskarnet
diff --git a/package/modes b/package/modes
index f65e285..40c11ba 100644
--- a/package/modes
+++ b/package/modes
@@ -9,6 +9,7 @@ false		0755
 link        0755
 ln          0755
 nice        0755
+nohup       0755
 renice      0755
 tee         0755
 true		0755
diff --git a/package/targets.mak b/package/targets.mak
index 8d0f48d..23fe74d 100644
--- a/package/targets.mak
+++ b/package/targets.mak
@@ -10,6 +10,7 @@ false \
 link \
 ln \
 nice \
+nohup \
 renice \
 tee \
 true \
diff --git a/src/shh-portable-utils/deps-exe/nohup b/src/shh-portable-utils/deps-exe/nohup
new file mode 100644
index 0000000..e7187fe
--- /dev/null
+++ b/src/shh-portable-utils/deps-exe/nohup
@@ -0,0 +1 @@
+-lskarnet
diff --git a/src/shh-portable-utils/nohup.c b/src/shh-portable-utils/nohup.c
new file mode 100644
index 0000000..8036940
--- /dev/null
+++ b/src/shh-portable-utils/nohup.c
@@ -0,0 +1,89 @@
+#include <stdlib.h>
+#include <errno.h>
+
+#include <unistd.h>
+#include <signal.h>
+#include <fcntl.h>
+
+#include <skalibs/strerr2.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+#define USAGE "nohup utility [argument...]"
+
+int open_nohupout(void);
+
+int main(int argc, char **argv)
+{
+    int new_fd;
+    int stdout_tty = 0, stdout_closed = 0;
+    int stderr_tty = 0;
+
+    PROG = "nohup";
+    if (argc < 2)
+        strerr_dieusage(127, USAGE);
+
+    if (signal(SIGHUP, SIG_IGN) == SIG_ERR)
+        strerr_diefu1sys(127, "set SIGHUP disposition");
+
+    stdout_tty = isatty(1);
+    if (errno == EBADF)
+        stdout_closed = 1;
+
+    stderr_tty = isatty(2);
+
+    /* configure io streams
+     *
+     * stdin */
+    if (stdout_tty) {
+        new_fd = open_nohupout();
+
+        if (dup2(new_fd, 1) == -1)
+            strerr_diefu1sys(127, "redirect stdin");
+
+        close(new_fd);
+    }
+
+    /* stderr */
+
+    if (stderr_tty) {
+        if (!stdout_closed) {
+            if (dup2(1, 2) == -1)
+                strerr_diefu1sys(127, "redirect stderr to stdin");
+        } else {
+            new_fd = open_nohupout();
+            if (dup2(new_fd, 2) == -1)
+                strerr_diefu1sys(127, "redirect stderr");
+            close(new_fd);
+        }
+    }
+
+    execvp(argv[1], argv + 1);
+    
+    if (errno == ENOENT)
+        return 127;
+    else
+        return 126;
+}
+
+int open_nohupout(void)
+{
+    char *homedir;
+    int homedir_fd;
+    int fd = open3("nohup.out", O_WRONLY | O_CREAT | O_APPEND, 0600);
+    if (fd == -1) {
+        strerr_warnwu1sys("open nohup.out");
+        homedir = getenv("HOME");
+        if (!homedir)
+            strerr_diefu1x(127, "get $HOME value");
+        homedir_fd = open2(homedir, O_RDONLY);
+        if (homedir_fd == -1)
+            strerr_diefu1sys(127, "open home directory");
+        fd = openat(homedir_fd, "nohup.out", O_WRONLY | O_CREAT | O_APPEND,
+                        0600);
+        if (fd == -1)
+            strerr_diefu3sys(127, "open ", homedir, "/nohup.out");
+        close(homedir_fd);
+    }
+    return fd;
+}