Implemented cmd_spawn and cmd_output actions

.gitignore

@@ -5,11 +5,11 @@
 /src/qtplugin.moc
 /src/qtplugin.o
 
+/src/action_c.o
 /src/failsafe.o
 /src/init.o
 /src/config.o
 /src/dlhook.o
-/src/action_c.o
 
 /src/menu.o
 /src/action_cc.o

res/doc

@@ -25,8 +25,8 @@
 #                   nickel_setting - toggles a boolean setting
 #                   nickel_extras  - opens one of the beta features
 #                   nickel_misc    - other stuff which isn't significant enough for its own category
-#                   cmdline_spawn  - starts another process or script in the background (TODO)
+#                   cmd_spawn      - starts another process or script in the background
-#                   cmdline_output - runs a command and displays the output (TODO)
+#                   cmd_output     - runs a command and displays the output
 #     <arg>       the argument passed to the action:
 #                   dbg_syslog     - the text to write
 #                   dbg_error      - the error message
@@ -44,6 +44,8 @@
 #                   misc           - one of:
 #                                      force_usb_connection - forces a usb connection dialog to be shown
 #                                      rescan_books         - forces nickel to rescan books (TODO)
+#                   cmd_spawn      - the command line to pass to /bin/sh -c (started in /)
+#                   cmd_output     - the timeout in milliseconds (0 < t < 10000), a colon, then the command line to pass to /bin/sh -c (started in /)
 #
 # For example, you might have a configuration file in KOBOeReader/.adds/nm/mystuff like:
 #

src/action_cc.cc

@@ -1,3 +1,9 @@
+#include <QProcess>
+#include <QString>
+#include <QStringList>
+
+#include <initializer_list>
+
 #include <alloca.h>
 #include <dlfcn.h>
 #include <errno.h>
@@ -150,3 +156,81 @@ extern "C" int nm_action_nickelmisc(const char *arg, char **err_out) {
     NM_RETURN_OK(0);
     #undef NM_ERR_RET
 }
+
+// TODO: stop abusing err_out to display messages, maybe add a msg_out arg
+// for that kind of thing instead (I've marked those spots by returning 2 for
+// now).
+
+extern "C" int nm_action_cmdspawn(const char *arg, char **err_out) {
+    #define NM_ERR_RET 1
+
+    QProcess proc;
+    uint64_t pid;
+    bool ok = proc.startDetached(
+        QStringLiteral("/bin/sh"),
+        QStringList(std::initializer_list<QString>{
+            QStringLiteral("-c"),
+            QString::fromUtf8(arg),
+        }),
+        QStringLiteral("/"),
+        (qint64*)(&pid)
+    );
+    NM_ASSERT(ok, "could not start process");
+
+    if (*err_out)
+        asprintf(err_out, "Successfully started process with PID %lu.", pid);
+    return 2;
+
+    #undef NM_ERR_RET
+}
+
+extern "C" int nm_action_cmdoutput(const char *arg, char **err_out) {
+    #define NM_ERR_RET 1
+
+    char *tmp = strdup(arg);
+
+    char *cmd = tmp;
+    char *tmp1 = strsep(&cmd, ":"), *tmp2;
+    long timeout = strtol(tmp1, &tmp2, 10);
+    NM_ASSERT(*tmp1 && !*tmp2 && timeout > 0 && timeout < 10000, "invalid timeout '%s'", tmp1);
+
+    QProcess proc;
+    proc.setProcessChannelMode(QProcess::MergedChannels);
+    proc.setWorkingDirectory(QStringLiteral("/"));
+    proc.start(
+        QStringLiteral("/bin/sh"),
+        QStringList(std::initializer_list<QString>{
+            QStringLiteral("-c"),
+            QString::fromUtf8(cmd),
+        }),
+        QIODevice::ReadOnly
+    );
+
+    bool ok = proc.waitForFinished(timeout);
+    if (!ok) {
+        switch (proc.error()) {
+        case QProcess::Timedout:
+            NM_RETURN_ERR("could not run process: timed out");
+        case QProcess::FailedToStart:
+            NM_RETURN_ERR("could not run process: missing program or wrong permissions");
+        case QProcess::Crashed:
+            NM_RETURN_ERR("could not run process: process crashed");
+        default:
+            NM_RETURN_ERR("could not run process");
+        }
+    }
+    if (proc.exitStatus() == QProcess::NormalExit && proc.exitCode() != 0)
+        NM_RETURN_ERR("could not run process: process exited with status %d", proc.exitCode());
+
+    QString out = proc.readAllStandardOutput();
+    if (out.length() > 500)
+        out = out.left(500) + "...";
+
+    free(tmp);
+
+    if (err_out)
+        *err_out = strdup(qPrintable(out));
+    return 2;
+
+    #undef NM_ERR_RET
+}

src/action_cc.h

@@ -4,9 +4,14 @@
 extern "C" {
 #endif
 
+// This file contains actions which need access to Qt classes, but is still
+// mostly C code.
+
 int nm_action_nickelsetting(const char *arg, char **err_out);
 int nm_action_nickelextras(const char *arg, char **err_out);
 int nm_action_nickelmisc(const char *arg, char **err_out);
+int nm_action_cmdspawn(const char *arg, char **err_out);
+int nm_action_cmdoutput(const char *arg, char **err_out);
 
 #ifdef __cplusplus
 }

src/config.c

@@ -132,6 +132,8 @@ nm_config_t *nm_config_parse(char **err_out) {
                 else if (!strcmp(c_act, "nickel_setting")) it->act = nm_action_nickelsetting;
                 else if (!strcmp(c_act, "nickel_extras"))  it->act = nm_action_nickelextras;
                 else if (!strcmp(c_act, "nickel_misc"))    it->act = nm_action_nickelmisc;
+                else if (!strcmp(c_act, "cmd_spawn"))      it->act = nm_action_cmdspawn;
+                else if (!strcmp(c_act, "cmd_output"))     it->act = nm_action_cmdoutput;
                 else RETERR("file %s: line %d: field 4: unknown action '%s'", fn, line_n, c_act);
 
                 // type: menu_item - field 5: argument