Add missing return value checks

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>

cansniffer.c

@@ -690,12 +690,15 @@ void writesettings(char* name){
 
 		for (i=0; i < 2048 ;i++) {
 			sprintf(buf, "<%03X>%c.", i, (is_set(i, ENABLE))?'1':'0');
-			write(fd, buf, 7);
+			if (write(fd, buf, 7) < 0)
+				perror("write");
 			for (j=0; j<8 ; j++){
 				sprintf(buf, "%02X", sniftab[i].notch.data[j]);
-				write(fd, buf, 2);
+				if (write(fd, buf, 2) < 0)
+					perror("write");
 			}
-			write(fd, "\n", 1);
+			if (write(fd, "\n", 1) < 0)
+				perror("write");
 			/* 7 + 16 + 1 = 24 bytes per entry */ 
 		}
 		close(fd);

jacd.c

@@ -484,7 +484,8 @@ int main(int argc, char *argv[])
 		break;
 	case 'p':
 #ifdef _GNU_SOURCE
-		asprintf(&program_invocation_name, "%s.%s", program_invocation_short_name, optarg);
+		if (asprintf(&program_invocation_name, "%s.%s", program_invocation_short_name, optarg) < 0)
+			error(1, errno, "asprintf(program invocation name)");
 #else
 		error(0, 0, "compile with -D_GNU_SOURCE to use -p");
 #endif

jsr.c

@@ -210,7 +210,8 @@ int main(int argc, char **argv)
 					exit(1);
 				}
 			} else {
-				write(STDOUT_FILENO, buf, ret);
+				if (write(STDOUT_FILENO, buf, ret) < 0)
+					error(1, errno, "write(stdout)");
 			}
 		}
 	}

slcan_attach.c

@@ -157,25 +157,40 @@ int main(int argc, char **argv)
 
 		if (speed) {
 			sprintf(buf, "C\rS%s\r", speed);
-			write(fd, buf, strlen(buf));
+			if (write(fd, buf, strlen(buf)) <= 0) {
+				perror("write");
+				exit(EXIT_FAILURE);
+			}
 		}
 
 		if (btr) {
 			sprintf(buf, "C\rs%s\r", btr);
-			write(fd, buf, strlen(buf));
+			if (write(fd, buf, strlen(buf)) <= 0) {
+				perror("write");
+				exit(EXIT_FAILURE);
+			}
 		}
 
 		if (send_read_status_flags) {
 			sprintf(buf, "F\r");
-			write(fd, buf, strlen(buf));
+			if (write(fd, buf, strlen(buf)) <= 0) {
+				perror("write");
+				exit(EXIT_FAILURE);
+			}
 		}
 
 		if (send_listen) {
 			sprintf(buf, "L\r");
-			write(fd, buf, strlen(buf));
+			if (write(fd, buf, strlen(buf)) <= 0) {
+				perror("write");
+				exit(EXIT_FAILURE);
+			}
 		} else if (send_open) {
 			sprintf(buf, "O\r");
-			write(fd, buf, strlen(buf));
+			if (write(fd, buf, strlen(buf)) <= 0) {
+				perror("write");
+				exit(EXIT_FAILURE);
+			}
 		}
 
 		/* set slcan line discipline on given tty */
@@ -229,7 +244,10 @@ int main(int argc, char **argv)
 
 		if (send_close) {
 			sprintf(buf, "C\r");
-			write(fd, buf, strlen(buf));
+			if (write(fd, buf, strlen(buf)) <= 0) {
+				perror("write");
+				exit(EXIT_FAILURE);
+			}
 		}
 	}
 

slcand.c

@@ -326,25 +326,40 @@ int main(int argc, char *argv[])
 
 	if (speed) {
 		sprintf(buf, "C\rS%s\r", speed);
-		write(fd, buf, strlen(buf));
+		if (write(fd, buf, strlen(buf)) <= 0) {
+			perror("write");
+			exit(EXIT_FAILURE);
+		}
 	}
 
 	if (btr) {
 		sprintf(buf, "C\rs%s\r", btr);
-		write(fd, buf, strlen(buf));
+		if (write(fd, buf, strlen(buf)) <= 0) {
+			perror("write");
+			exit(EXIT_FAILURE);
+		}
 	}
 
 	if (send_read_status_flags) {
 		sprintf(buf, "F\r");
-		write(fd, buf, strlen(buf));
+		if (write(fd, buf, strlen(buf)) <= 0) {
+			perror("write");
+			exit(EXIT_FAILURE);
+		}
 	}
 
 	if (send_listen) {
 		sprintf(buf, "L\r");
-		write(fd, buf, strlen(buf));
+		if (write(fd, buf, strlen(buf)) <= 0) {
+			perror("write");
+			exit(EXIT_FAILURE);
+		}
 	} else if (send_open) {
 		sprintf(buf, "O\r");
-		write(fd, buf, strlen(buf));
+		if (write(fd, buf, strlen(buf)) <= 0) {
+			perror("write");
+			exit(EXIT_FAILURE);
+		}
 	}
 
 	/* set slcan like discipline on given tty */
@@ -412,7 +427,10 @@ int main(int argc, char *argv[])
 
 	if (send_close) {
 		sprintf(buf, "C\r");
-		write(fd, buf, strlen(buf));
+		if (write(fd, buf, strlen(buf)) <= 0) {
+			perror("write");
+			exit(EXIT_FAILURE);
+		}
 	}
 
 	/* Reset old rates */