Adding ability to specify timeout for tail widget when following a file

3 files changed, 35 insertions, 3 deletions

diff --git a/src/securecoreutils.h b/src/securecoreutils.h
index b29a16c..ff1990f 100644
--- a/src/securecoreutils.h
+++ b/src/securecoreutils.h
@@ -85,6 +85,11 @@
 #endif
 
 
+#ifndef SCU_TAIL_TIMEOUT
+#define SCU_TAIL_TIMEOUT 0
+#endif
+
+
 #ifdef LINE_MAX
 #   define SCU_LINE_MAX LINE_MAX
 #elif defined _POSIX2_LINE_MAX
diff --git a/src/widget-tail.c b/src/widget-tail.c
index 63ef5a4..69ed7c3 100644
--- a/src/widget-tail.c
+++ b/src/widget-tail.c
@@ -54,6 +54,7 @@
 #include <unistd.h>
 #include <stdlib.h>
 #include <time.h>
+#include <signal.h>
 
 
 ///////////////////
@@ -80,6 +81,15 @@ int scu_widget_tail_lines(scu_config * cnf, int fd, struct stat * sb,
    size_t opts, off_t optnum);
 
 
+////////////////
+//            //
+//  Variable  //
+//            //
+////////////////
+
+static int timeout_alarmed = 0;
+
+
 /////////////////
 //             //
 //  Functions  //
@@ -332,10 +342,16 @@ int scu_widget_tail_follow(scu_config * cnf, int fd)
    ssize_t           len;
    struct timespec   ts;
 
-   ts.tv_sec  = 0;
-   ts.tv_nsec = 10000000;
+   ts.tv_sec       = 0;
+   ts.tv_nsec      = 10000000;
+   timeout_alarmed = 0;
+
+#if (SCU_TAIL_TIMEOUT > 0)
+   signal(SIGALRM, scu_widget_tail_follow_alarm);
+   alarm(SCU_TAIL_TIMEOUT);
+#endif
 
-   while (1)
+   while (!(timeout_alarmed))
    {
       switch (len = read(fd, buff, sizeof(buff)))
       {
@@ -361,6 +377,16 @@ int scu_widget_tail_follow(scu_config * cnf, int fd)
 }
 
 
+void scu_widget_tail_follow_alarm(int sig)
+{
+   timeout_alarmed = 1;
+   signal (sig, scu_widget_tail_follow_alarm);
+   alarm(1);
+   fprintf(stderr, "\n\n*** TAIL WIDGET TIMEOUT EXPIRED ***\n\n\n");
+   return;
+}
+
+
 int scu_widget_tail_lines(scu_config * cnf, int fd, struct stat * sb,
    size_t opts, off_t optnum)
 {
diff --git a/src/widget-tail.h b/src/widget-tail.h
index 62ab0cf..f4aedcd 100644
--- a/src/widget-tail.h
+++ b/src/widget-tail.h
@@ -63,5 +63,6 @@
 int scu_widget_tail(scu_config * cnf);
 
 void scu_widget_tail_usage(scu_config * cnf);
+void scu_widget_tail_follow_alarm(int sig);
 
 #endif /* end of header */