Move usage text into usage_str var

For consistency and readability.

Note: This also makes exactly one extra blank line be printed at the end
of every usage text, which is currently only done in the following
files:

* src/fcopy/main.c
* src/fnettrace-dns/main.c
* src/fnettrace-icmp/main.c
* src/fnettrace-sni/main.c
* src/fnettrace/main.c
* src/profstats/main.c

19 files changed, 153 insertions, 122 deletions

diff --git a/src/etc-cleanup/main.c b/src/etc-cleanup/main.c
index 6c7bea6d6..f15ba53cd 100644
--- a/src/etc-cleanup/main.c
+++ b/src/etc-cleanup/main.c
@@ -212,13 +212,16 @@ static void process_file(const char *fname) {
         }
 }
 
+static const char *const usage_str =
+        "usage: cleanup-etc [options] file.profile [file.profile]\n"
+        "Group and clean private-etc entries in one or more profile files.\n"
+        "Options:\n"
+        "   --debug - print debug messages\n"
+        "   -h, -?, --help - this help screen\n"
+        "   --replace - replace profile file\n";
+
 static void usage(void) {
-        printf("usage: cleanup-etc [options] file.profile [file.profile]\n");
-        printf("Group and clean private-etc entries in one or more profile files.\n");
-        printf("Options:\n");
-        printf("   --debug - print debug messages\n");
-        printf("   -h, -?, --help - this help screen\n");
-        printf("   --replace - replace profile file\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/fbuilder/main.c b/src/fbuilder/main.c
index 7fdf9af68..a85d4a931 100644
--- a/src/fbuilder/main.c
+++ b/src/fbuilder/main.c
@@ -21,9 +21,12 @@
 int arg_debug = 0;
 int arg_appimage = 0;
 
+static const char *const usage_str =
+        "Firejail profile builder\n"
+        "Usage: firejail [--debug] --build[=profile-file] program-and-arguments\n";
+
 static void usage(void) {
-        printf("Firejail profile builder\n");
-        printf("Usage: firejail [--debug] --build[=profile-file] program-and-arguments\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/fcopy/main.c b/src/fcopy/main.c
index ce2efb295..a56e8a91b 100644
--- a/src/fcopy/main.c
+++ b/src/fcopy/main.c
@@ -416,18 +416,19 @@ static void duplicate_link(const char *src, const char *dest, struct stat *s) {
         free(rdest);
 }
 
+static const char *const usage_str =
+        "Usage: fcopy [--follow-link] src dest\n"
+        "\n"
+        "Copy SRC to DEST/SRC. SRC may be a file, directory, or symbolic link.\n"
+        "If SRC is a directory it is copied recursively.  If it is a symlink,\n"
+        "the link itself is duplicated, unless --follow-link is given,\n"
+        "in which case the destination of the link is copied.\n"
+        "DEST must already exist and must be a directory.\n";
 
 static void usage(void) {
-        fputs("Usage: fcopy [--follow-link] src dest\n"
-                "\n"
-                "Copy SRC to DEST/SRC. SRC may be a file, directory, or symbolic link.\n"
-                "If SRC is a directory it is copied recursively.  If it is a symlink,\n"
-                "the link itself is duplicated, unless --follow-link is given,\n"
-                "in which case the destination of the link is copied.\n"
-                "DEST must already exist and must be a directory.\n", stderr);
+        fputs(usage_str, stderr);
 }
 
-
 int main(int argc, char **argv) {
 #if 0
         {
diff --git a/src/fids/main.c b/src/fids/main.c
index f1dfdac8e..915edb6ca 100644
--- a/src/fids/main.c
+++ b/src/fids/main.c
@@ -318,10 +318,11 @@ static void process_config(const char *fname) {
         include_level--;
 }
 
-
+static const char *const usage_str =
+        "Usage: fids [--help|-h|-?] --init|--check homedir\n";
 
 void usage(void) {
-        printf("Usage: fids [--help|-h|-?] --init|--check homedir\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/firecfg/main.c b/src/firecfg/main.c
index 855523e55..aadc93579 100644
--- a/src/firecfg/main.c
+++ b/src/firecfg/main.c
@@ -57,7 +57,7 @@ static const char *const usage_str =
         "   [...]\n"
         "\n"
         "License GPL version 2 or later\n"
-        "Homepage: https://firejail.wordpress.com\n\n";
+        "Homepage: https://firejail.wordpress.com\n";
 
 static void print_version(void) {
         printf("firecfg version %s\n\n", VERSION);
diff --git a/src/firejail/usage.c b/src/firejail/usage.c
index 00a86f426..e8758c807 100644
--- a/src/firejail/usage.c
+++ b/src/firejail/usage.c
@@ -311,8 +311,7 @@ static const char *const usage_str =
         "\tlist all running sandboxes\n"
         "\n"
         "License GPL version 2 or later\n"
-        "Homepage: https://firejail.wordpress.com\n"
-        "\n";
+        "Homepage: https://firejail.wordpress.com\n";
 
 void print_version(void) {
         printf("firejail version %s\n\n", VERSION);
diff --git a/src/firemon/usage.c b/src/firemon/usage.c
index 411fc1600..afd2b552a 100644
--- a/src/firemon/usage.c
+++ b/src/firemon/usage.c
@@ -75,8 +75,7 @@ static const char *const usage_str =
         "\tUser - The owner of the sandbox.\n"
         "\n"
         "License GPL version 2 or later\n"
-        "Homepage: https://firejail.wordpress.com\n"
-        "\n";
+        "Homepage: https://firejail.wordpress.com\n";
 
 void print_version(void) {
         printf("firemon version %s\n\n", VERSION);
diff --git a/src/fldd/main.c b/src/fldd/main.c
index 63398ce2e..c28cad72e 100644
--- a/src/fldd/main.c
+++ b/src/fldd/main.c
@@ -282,12 +282,13 @@ static void walk_directory(const char *dirname) {
         }
 }
 
-
+static const char *const usage_str =
+        "Usage: fldd program_or_directory [file]\n"
+        "Print a list of libraries used by program or store it in the file.\n"
+        "Print a list of libraries used by all .so files in a directory or store it in the file.\n";
 
 static void usage(void) {
-        printf("Usage: fldd program_or_directory [file]\n");
-        printf("Print a list of libraries used by program or store it in the file.\n");
-        printf("Print a list of libraries used by all .so files in a directory or store it in the file.\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
@@ -363,4 +364,4 @@ int main(void) {
         printf("Sorry, private lib is disabled in this build\n");
         return 0;
 }
-#endif
\ No newline at end of file
+#endif
diff --git a/src/fnet/main.c b/src/fnet/main.c
index fc36ae977..d1c8170ca 100644
--- a/src/fnet/main.c
+++ b/src/fnet/main.c
@@ -35,19 +35,21 @@ void fmessage(char* fmt, ...) { // TODO: this function is duplicated in src/fire
         fflush(0);
 }
 
+static const char *const usage_str =
+        "Usage:\n"
+        "\tfnet create veth dev1 dev2 bridge child\n"
+        "\tfnet create macvlan dev parent child\n"
+        "\tfnet moveif dev proc\n"
+        "\tfnet printif\n"
+        "\tfnet printif scan\n"
+        "\tfnet config interface dev ip mask mtu\n"
+        "\tfnet config mac addr\n"
+        "\tfnet config ipv6 dev ip\n"
+        "\tfnet ifup dev\n"
+        "\tfnet waitll dev\n";
 
 static void usage(void) {
-        printf("Usage:\n");
-        printf("\tfnet create veth dev1 dev2 bridge child\n");
-        printf("\tfnet create macvlan dev parent child\n");
-        printf("\tfnet moveif dev proc\n");
-        printf("\tfnet printif\n");
-        printf("\tfnet printif scan\n");
-        printf("\tfnet config interface dev ip mask mtu\n");
-        printf("\tfnet config mac addr\n");
-        printf("\tfnet config ipv6 dev ip\n");
-        printf("\tfnet ifup dev\n");
-        printf("\tfnet waitll dev\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/fnetfilter/main.c b/src/fnetfilter/main.c
index 8c0f6c297..1b0335d68 100644
--- a/src/fnetfilter/main.c
+++ b/src/fnetfilter/main.c
@@ -45,9 +45,12 @@ static char *default_filter =
 "-A OUTPUT -p tcp --dport 3479 -j DROP\n"
 "COMMIT\n";
 
+static const char *const usage_str =
+        "Usage:\n"
+        "\tfnetfilter netfilter-command destination-file\n";
+
 static void usage(void) {
-        printf("Usage:\n");
-        printf("\tfnetfilter netfilter-command destination-file\n");
+        puts(usage_str);
 }
 
 static void err_exit_cannot_open_file(const char *fname) {
diff --git a/src/fnettrace-dns/main.c b/src/fnettrace-dns/main.c
index 64feec5fe..1cde1942c 100644
--- a/src/fnettrace-dns/main.c
+++ b/src/fnettrace-dns/main.c
@@ -167,13 +167,13 @@ static void run_trace(void) {
 
         close(s);
 }
-
+static const char *const usage_str =
+        "Usage: fnettrace-dns [OPTIONS]\n"
+        "Options:\n"
+        "   --help, -? - this help screen\n";
 
 static void usage(void) {
-        printf("Usage: fnettrace-dns [OPTIONS]\n");
-        printf("Options:\n");
-        printf("   --help, -? - this help screen\n");
-        printf("\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/fnettrace-icmp/main.c b/src/fnettrace-icmp/main.c
index 714917547..516a9fc5b 100644
--- a/src/fnettrace-icmp/main.c
+++ b/src/fnettrace-icmp/main.c
@@ -201,11 +201,13 @@ static void run_trace(void) {
         close(s);
 }
 
+static const char *const usage_str =
+        "Usage: fnettrace-icmp [OPTIONS]\n"
+        "Options:\n"
+        "   --help, -? - this help screen\n";
+
 static void usage(void) {
-        printf("Usage: fnettrace-icmp [OPTIONS]\n");
-        printf("Options:\n");
-        printf("   --help, -? - this help screen\n");
-        printf("\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/fnettrace-sni/main.c b/src/fnettrace-sni/main.c
index b8490b4f7..e7782d656 100644
--- a/src/fnettrace-sni/main.c
+++ b/src/fnettrace-sni/main.c
@@ -204,12 +204,13 @@ static void run_trace(void) {
         close(s);
 }
 
+static const char *const usage_str =
+        "Usage: fnettrace-sni [OPTIONS]\n"
+        "Options:\n"
+        "   --help, -? - this help screen\n";
 
 static void usage(void) {
-        printf("Usage: fnettrace-sni [OPTIONS]\n");
-        printf("Options:\n");
-        printf("   --help, -? - this help screen\n");
-        printf("\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/fnettrace/main.c b/src/fnettrace/main.c
index 2f421562e..178ac3631 100644
--- a/src/fnettrace/main.c
+++ b/src/fnettrace/main.c
@@ -668,18 +668,20 @@ void logprintf(char *fmt, ...) {
         va_end(args);
 }
 
+static const char *const usage_str =
+        "Usage: fnettrace [OPTIONS]\n"
+        "Options:\n"
+        "   --help, -? - this help screen\n"
+        "   --log=filename - netlocker logfile\n"
+        "   --netfilter - build the firewall rules and commit them.\n"
+        "   --tail - \"tail -f\" functionality\n"
+        "Examples:\n"
+        "   # fnettrace                              - traffic trace\n"
+        "   # fnettrace --netfilter --log=logfile    - netlocker, dump output in logfile\n"
+        "   # fnettrace --tail --log=logifile        - similar to \"tail -f logfile\"\n";
+
 static void usage(void) {
-        printf("Usage: fnettrace [OPTIONS]\n");
-        printf("Options:\n");
-        printf("   --help, -? - this help screen\n");
-        printf("   --log=filename - netlocker logfile\n");
-        printf("   --netfilter - build the firewall rules and commit them.\n");
-        printf("   --tail - \"tail -f\" functionality\n");
-        printf("Examples:\n");
-        printf("   # fnettrace                              - traffic trace\n");
-        printf("   # fnettrace --netfilter --log=logfile    - netlocker, dump output in logfile\n");
-        printf("   # fnettrace --tail --log=logifile        - similar to \"tail -f logfile\"\n");
-        printf("\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/fsec-optimize/main.c b/src/fsec-optimize/main.c
index 0bc521c0d..38ba7c697 100644
--- a/src/fsec-optimize/main.c
+++ b/src/fsec-optimize/main.c
@@ -22,9 +22,12 @@
 
 int arg_seccomp_error_action = SECCOMP_RET_ERRNO | EPERM; // error action: errno, log or kill
 
+static const char *const usage_str =
+        "Usage:\n"
+        "\tfsec-optimize file - optimize seccomp filter\n";
+
 static void usage(void) {
-        printf("Usage:\n");
-        printf("\tfsec-optimize file - optimize seccomp filter\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/fsec-print/main.c b/src/fsec-print/main.c
index 696c6bc0c..4d3e38648 100644
--- a/src/fsec-print/main.c
+++ b/src/fsec-print/main.c
@@ -19,9 +19,12 @@
 */
 #include "fsec_print.h"
 
+static const char *const usage_str =
+        "Usage:\n"
+        "\tfsec-print file - disassemble seccomp filter\n";
+
 static void usage(void) {
-        printf("Usage:\n");
-        printf("\tfsec-print file - disassemble seccomp filter\n");
+        puts(usage_str);
 }
 
 int arg_quiet = 0;
diff --git a/src/fseccomp/main.c b/src/fseccomp/main.c
index 0b46daf65..e7823d3c5 100644
--- a/src/fseccomp/main.c
+++ b/src/fseccomp/main.c
@@ -22,34 +22,37 @@
 int arg_quiet = 0;
 int arg_seccomp_error_action = SECCOMP_RET_ERRNO | EPERM; // error action: errno, log or kill
 
+static const char *const usage_str =
+        "Usage:\n"
+        "\tfseccomp debug-syscalls\n"
+        "\tfseccomp debug-syscalls32\n"
+        "\tfseccomp debug-errnos\n"
+        "\tfseccomp debug-protocols\n"
+        "\tfseccomp protocol build list file\n"
+        "\tfseccomp secondary 64 file\n"
+        "\tfseccomp secondary 32 file\n"
+        "\tfseccomp secondary block file\n"
+        "\tfseccomp default file\n"
+        "\tfseccomp default file allow-debuggers\n"
+        "\tfseccomp default32 file\n"
+        "\tfseccomp default32 file allow-debuggers\n"
+        "\tfseccomp drop file1 file2 list\n"
+        "\tfseccomp drop file1 file2 list allow-debuggers\n"
+        "\tfseccomp drop32 file1 file2 list\n"
+        "\tfseccomp drop32 file1 file2 list allow-debuggers\n"
+        "\tfseccomp default drop file1 file2 list\n"
+        "\tfseccomp default drop file1 file2 list allow-debuggers\n"
+        "\tfseccomp default32 drop file1 file2 list\n"
+        "\tfseccomp default32 drop file1 file2 list allow-debuggers\n"
+        "\tfseccomp keep file1 file2 list\n"
+        "\tfseccomp keep32 file1 file2 list\n"
+        "\tfseccomp memory-deny-write-execute file\n"
+        "\tfseccomp memory-deny-write-execute.32 file\n"
+        "\tfseccomp restrict-namespaces file list\n"
+        "\tfseccomp restrict-namespaces.32 file list\n";
+
 static void usage(void) {
-        printf("Usage:\n"
-                "\tfseccomp debug-syscalls\n"
-                "\tfseccomp debug-syscalls32\n"
-                "\tfseccomp debug-errnos\n"
-                "\tfseccomp debug-protocols\n"
-                "\tfseccomp protocol build list file\n"
-                "\tfseccomp secondary 64 file\n"
-                "\tfseccomp secondary 32 file\n"
-                "\tfseccomp secondary block file\n"
-                "\tfseccomp default file\n"
-                "\tfseccomp default file allow-debuggers\n"
-                "\tfseccomp default32 file\n"
-                "\tfseccomp default32 file allow-debuggers\n"
-                "\tfseccomp drop file1 file2 list\n"
-                "\tfseccomp drop file1 file2 list allow-debuggers\n"
-                "\tfseccomp drop32 file1 file2 list\n"
-                "\tfseccomp drop32 file1 file2 list allow-debuggers\n"
-                "\tfseccomp default drop file1 file2 list\n"
-                "\tfseccomp default drop file1 file2 list allow-debuggers\n"
-                "\tfseccomp default32 drop file1 file2 list\n"
-                "\tfseccomp default32 drop file1 file2 list allow-debuggers\n"
-                "\tfseccomp keep file1 file2 list\n"
-                "\tfseccomp keep32 file1 file2 list\n"
-                "\tfseccomp memory-deny-write-execute file\n"
-                "\tfseccomp memory-deny-write-execute.32 file\n"
-                "\tfseccomp restrict-namespaces file list\n"
-                "\tfseccomp restrict-namespaces.32 file list\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/ftee/main.c b/src/ftee/main.c
index 0a492b41e..a34a76b26 100644
--- a/src/ftee/main.c
+++ b/src/ftee/main.c
@@ -180,8 +180,11 @@ static int is_link(const char *fname) {
         return 0;
 }
 
+static const char *const usage_str =
+        "Usage: ftee filename\n";
+
 static void usage(void) {
-        printf("Usage: ftee filename\n");
+        puts(usage_str);
 }
 
 int main(int argc, char **argv) {
diff --git a/src/profstats/main.c b/src/profstats/main.c
index d5e57e7cc..49ed1637a 100644
--- a/src/profstats/main.c
+++ b/src/profstats/main.c
@@ -74,32 +74,34 @@ static int arg_restrict_namespaces = 0;
 
 static char *profile = NULL;
 
+static const char *const usage_str =
+        "profstats - print profile statistics\n"
+        "Usage: profstats [options] file[s]\n"
+        "Options:\n"
+        "   --apparmor - print profiles without apparmor\n"
+        "   --caps - print profiles without caps\n"
+        "   --dbus-system-none - print profiles without \"dbus-system none\"\n"
+        "   --dbus-user-none - print profiles without \"dbus-user none\"\n"
+        "   --ssh - print profiles without \"include disable-common.inc\"\n"
+        "   --noexec - print profiles without \"include disable-exec.inc\"\n"
+        "   --noroot - print profiles without \"noroot\"\n"
+        "   --private-bin - print profiles without private-bin\n"
+        "   --private-dev - print profiles without private-dev\n"
+        "   --private-etc - print profiles without private-etc\n"
+        "   --private-tmp - print profiles without private-tmp\n"
+        "   --print-blacklist - print all --blacklist for a profile\n"
+        "   --print-whitelist - print all --private and --whitelist for a profile\n"
+        "   --seccomp - print profiles without seccomp\n"
+        "   --memory-deny-write-execute - print profiles without \"memory-deny-write-execute\"\n"
+        "   --restrict-namespaces - print profiles without \"restrict-namespaces\"\n"
+        "   --whitelist-home - print profiles whitelisting home directory\n"
+        "   --whitelist-var - print profiles without \"include whitelist-var-common.inc\"\n"
+        "   --whitelist-runuser - print profiles without \"include whitelist-runuser-common.inc\" or \"blacklist ${RUNUSER}\"\n"
+        "   --whitelist-usrshare - print profiles without \"include whitelist-usr-share-common.inc\"\n"
+        "   --debug\n";
+
 static void usage(void) {
-        printf("profstats - print profile statistics\n");
-        printf("Usage: profstats [options] file[s]\n");
-        printf("Options:\n");
-        printf("   --apparmor - print profiles without apparmor\n");
-        printf("   --caps - print profiles without caps\n");
-        printf("   --dbus-system-none - print profiles without \"dbus-system none\"\n");
-        printf("   --dbus-user-none - print profiles without \"dbus-user none\"\n");
-        printf("   --ssh - print profiles without \"include disable-common.inc\"\n");
-        printf("   --noexec - print profiles without \"include disable-exec.inc\"\n");
-        printf("   --noroot - print profiles without \"noroot\"\n");
-        printf("   --private-bin - print profiles without private-bin\n");
-        printf("   --private-dev - print profiles without private-dev\n");
-        printf("   --private-etc - print profiles without private-etc\n");
-        printf("   --private-tmp - print profiles without private-tmp\n");
-        printf("   --print-blacklist - print all --blacklist for a profile\n");
-        printf("   --print-whitelist - print all --private and --whitelist for a profile\n");
-        printf("   --seccomp - print profiles without seccomp\n");
-        printf("   --memory-deny-write-execute - print profiles without \"memory-deny-write-execute\"\n");
-        printf("   --restrict-namespaces - print profiles without \"restrict-namespaces\"\n");
-        printf("   --whitelist-home - print profiles whitelisting home directory\n");
-        printf("   --whitelist-var - print profiles without \"include whitelist-var-common.inc\"\n");
-        printf("   --whitelist-runuser - print profiles without \"include whitelist-runuser-common.inc\" or \"blacklist ${RUNUSER}\"\n");
-        printf("   --whitelist-usrshare - print profiles without \"include whitelist-usr-share-common.inc\"\n");
-        printf("   --debug\n");
-        printf("\n");
+        puts(usage_str);
 }
 
 static void process_file(char *fname) {