Replace all uses of sprintf with snprintf

In all the cases where sprintf was being used within htop, snprintf
could have been used. This patch replaces all uses of sprintf with
snprintf which makes sure that if a buffer is too small to hold the
resulting string, the string is simply cut short instead of causing
a buffer overflow which leads to undefined behaviour.

`sizeof(variable)` was used in these cases, as opposed to `sizeof
variable` which is my personal preference because `sizeof(variable)`
was already used in one way or another in other parts of the code.

6 files changed, 25 insertions, 25 deletions

diff --git a/CPUMeter.c b/CPUMeter.c
index 32bad049..6b9b83db 100644
--- a/CPUMeter.c
+++ b/CPUMeter.c
@@ -48,7 +48,7 @@ static void CPUMeter_init(Meter* this) {
    int cpu = this->param;
    if (this->pl->cpuCount > 1) {
       char caption[10];
-      sprintf(caption, "%-3d", Settings_cpuId(this->pl->settings, cpu - 1));
+      snprintf(caption, sizeof(caption), "%-3d", Settings_cpuId(this->pl->settings, cpu - 1));
       Meter_setCaption(this, caption);
    }
    if (this->param == 0)
@@ -74,44 +74,44 @@ static void CPUMeter_display(Object* cast, RichString* out) {
       RichString_append(out, CRT_colors[METER_TEXT], "absent");
       return;
    }
-   sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_NORMAL]);
+   snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_NORMAL]);
    RichString_append(out, CRT_colors[METER_TEXT], ":");
    RichString_append(out, CRT_colors[CPU_NORMAL], buffer);
    if (this->pl->settings->detailedCPUTime) {
-      sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_KERNEL]);
+      snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_KERNEL]);
       RichString_append(out, CRT_colors[METER_TEXT], "sy:");
       RichString_append(out, CRT_colors[CPU_KERNEL], buffer);
-      sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_NICE]);
+      snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_NICE]);
       RichString_append(out, CRT_colors[METER_TEXT], "ni:");
       RichString_append(out, CRT_colors[CPU_NICE_TEXT], buffer);
-      sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_IRQ]);
+      snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_IRQ]);
       RichString_append(out, CRT_colors[METER_TEXT], "hi:");
       RichString_append(out, CRT_colors[CPU_IRQ], buffer);
-      sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_SOFTIRQ]);
+      snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_SOFTIRQ]);
       RichString_append(out, CRT_colors[METER_TEXT], "si:");
       RichString_append(out, CRT_colors[CPU_SOFTIRQ], buffer);
       if (this->values[CPU_METER_STEAL]) {
-         sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_STEAL]);
+         snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_STEAL]);
          RichString_append(out, CRT_colors[METER_TEXT], "st:");
          RichString_append(out, CRT_colors[CPU_STEAL], buffer);
       }
       if (this->values[CPU_METER_GUEST]) {
-         sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_GUEST]);
+         snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_GUEST]);
          RichString_append(out, CRT_colors[METER_TEXT], "gu:");
          RichString_append(out, CRT_colors[CPU_GUEST], buffer);
       }
-      sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_IOWAIT]);
+      snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_IOWAIT]);
       RichString_append(out, CRT_colors[METER_TEXT], "wa:");
       RichString_append(out, CRT_colors[CPU_IOWAIT], buffer);
    } else {
-      sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_KERNEL]);
+      snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_KERNEL]);
       RichString_append(out, CRT_colors[METER_TEXT], "sys:");
       RichString_append(out, CRT_colors[CPU_KERNEL], buffer);
-      sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_NICE]);
+      snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_NICE]);
       RichString_append(out, CRT_colors[METER_TEXT], "low:");
       RichString_append(out, CRT_colors[CPU_NICE_TEXT], buffer);
       if (this->values[CPU_METER_IRQ]) {
-         sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_IRQ]);
+         snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_IRQ]);
          RichString_append(out, CRT_colors[METER_TEXT], "vir:");
          RichString_append(out, CRT_colors[CPU_GUEST], buffer);
       }
diff --git a/LoadAverageMeter.c b/LoadAverageMeter.c
index 54e517a8..517031dd 100644
--- a/LoadAverageMeter.c
+++ b/LoadAverageMeter.c
@@ -28,11 +28,11 @@ static void LoadAverageMeter_updateValues(Meter* this, char* buffer, int size) {
 static void LoadAverageMeter_display(Object* cast, RichString* out) {
    Meter* this = (Meter*)cast;
    char buffer[20];
-   sprintf(buffer, "%.2f ", this->values[0]);
+   snprintf(buffer, sizeof(buffer), "%.2f ", this->values[0]);
    RichString_write(out, CRT_colors[LOAD_AVERAGE_ONE], buffer);
-   sprintf(buffer, "%.2f ", this->values[1]);
+   snprintf(buffer, sizeof(buffer), "%.2f ", this->values[1]);
    RichString_append(out, CRT_colors[LOAD_AVERAGE_FIVE], buffer);
-   sprintf(buffer, "%.2f ", this->values[2]);
+   snprintf(buffer, sizeof(buffer), "%.2f ", this->values[2]);
    RichString_append(out, CRT_colors[LOAD_AVERAGE_FIFTEEN], buffer);
 }
 
@@ -48,7 +48,7 @@ static void LoadMeter_updateValues(Meter* this, char* buffer, int size) {
 static void LoadMeter_display(Object* cast, RichString* out) {
    Meter* this = (Meter*)cast;
    char buffer[20];
-   sprintf(buffer, "%.2f ", ((Meter*)this)->values[0]);
+   snprintf(buffer, sizeof(buffer), "%.2f ", ((Meter*)this)->values[0]);
    RichString_write(out, CRT_colors[LOAD], buffer);
 }
 
diff --git a/Process.c b/Process.c
index a1ffcf0e..fea5533c 100644
--- a/Process.c
+++ b/Process.c
@@ -198,7 +198,7 @@ void Process_setupColumnWidths() {
       snprintf(Process_titleBuffer[i], 20, "%*s ", digits, Process_pidColumns[i].label);
       Process_fields[Process_pidColumns[i].id].title = Process_titleBuffer[i];
    }
-   sprintf(Process_pidFormat, "%%%dd ", digits);
+   snprintf(Process_pidFormat, sizeof(Process_pidFormat), "%%%dd ", digits);
 }
 
 void Process_humanNumber(RichString* str, unsigned long number, bool coloring) {
diff --git a/TasksMeter.c b/TasksMeter.c
index 78a14683..3e695319 100644
--- a/TasksMeter.c
+++ b/TasksMeter.c
@@ -40,7 +40,7 @@ static void TasksMeter_display(Object* cast, RichString* out) {
    
    int processes = (int) this->values[2];
    
-   sprintf(buffer, "%d", processes);
+   snprintf(buffer, sizeof(buffer), "%d", processes);
    RichString_write(out, CRT_colors[METER_VALUE], buffer);
    int threadValueColor = CRT_colors[METER_VALUE];
    int threadCaptionColor = CRT_colors[METER_TEXT];
@@ -50,18 +50,18 @@ static void TasksMeter_display(Object* cast, RichString* out) {
    }
    if (!settings->hideUserlandThreads) {
       RichString_append(out, CRT_colors[METER_TEXT], ", ");
-      sprintf(buffer, "%d", (int)this->values[1]);
+      snprintf(buffer, sizeof(buffer), "%d", (int)this->values[1]);
       RichString_append(out, threadValueColor, buffer);
       RichString_append(out, threadCaptionColor, " thr");
    }
    if (!settings->hideKernelThreads) {
       RichString_append(out, CRT_colors[METER_TEXT], ", ");
-      sprintf(buffer, "%d", (int)this->values[0]);
+      snprintf(buffer, sizeof(buffer), "%d", (int)this->values[0]);
       RichString_append(out, threadValueColor, buffer);
       RichString_append(out, threadCaptionColor, " kthr");
    }
    RichString_append(out, CRT_colors[METER_TEXT], "; ");
-   sprintf(buffer, "%d", (int)this->values[3]);
+   snprintf(buffer, sizeof(buffer), "%d", (int)this->values[3]);
    RichString_append(out, CRT_colors[TASKS_RUNNING], buffer);
    RichString_append(out, CRT_colors[METER_TEXT], " running");
 }
diff --git a/TraceScreen.c b/TraceScreen.c
index 2d6eb336..bd771182 100644
--- a/TraceScreen.c
+++ b/TraceScreen.c
@@ -99,7 +99,7 @@ bool TraceScreen_forkTracer(TraceScreen* this) {
       dup2(this->fdpair[1], STDERR_FILENO);
       int ok = fcntl(this->fdpair[1], F_SETFL, O_NONBLOCK);
       if (ok != -1) {
-         sprintf(buffer, "%d", this->super.process->pid);
+         snprintf(buffer, sizeof(buffer), "%d", this->super.process->pid);
          execlp("strace", "strace", "-p", buffer, NULL);
       }
       const char* message = "Could not execute 'strace'. Please make sure it is available in your $PATH.";
diff --git a/UptimeMeter.c b/UptimeMeter.c
index d20c4797..2fe603ae 100644
--- a/UptimeMeter.c
+++ b/UptimeMeter.c
@@ -33,11 +33,11 @@ static void UptimeMeter_updateValues(Meter* this, char* buffer, int len) {
    }
    char daysbuf[15];
    if (days > 100) {
-      sprintf(daysbuf, "%d days(!), ", days);
+      snprintf(daysbuf, sizeof(daysbuf), "%d days(!), ", days);
    } else if (days > 1) {
-      sprintf(daysbuf, "%d days, ", days);
+      snprintf(daysbuf, sizeof(daysbuf), "%d days, ", days);
    } else if (days == 1) {
-      sprintf(daysbuf, "1 day, ");
+      snprintf(daysbuf, sizeof(daysbuf), "1 day, ");
    } else {
       daysbuf[0] = '\0';
    }