lib/, src/: Use streq() instead of its pattern

Except for the added (and sorted) includes, the removal of redundant
parentheses, a few cases that have been refactored for readability, and
a couple of non-string cases that I've left out of the change, this
patch can be approximated with the following semantic patch:

	$ cat ~/tmp/spatch/streq.sp
	@@
	expression s;
	@@

	- '\0' == *s
	+ streq(s, "")

	@@
	expression s;
	@@

	- '\0' == s[0]
	+ streq(s, "")

	@@
	expression s;
	@@

	- *s == '\0'
	+ streq(s, "")

	@@
	expression s;
	@@

	- s[0] == '\0'
	+ streq(s, "")

	$ find contrib/ lib* src/ -type f \
	| xargs spatch --in-place --sp-file ~/tmp/spatch/streq.sp;

Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/getdef.c

@@ -567,7 +567,7 @@ static void def_load (void)
 		 * Break the line into two fields.
 		 */
 		name = stpspn(buf, " \t");	/* first nonwhite */
-		if (*name == '\0' || *name == '#')
+		if (streq(name, "") || *name == '#')
 			continue;	/* comment or empty */
 
 		s = stpsep(name, " \t");  /* next field */

lib/getrange.c

@@ -13,6 +13,7 @@
 #include "atoi/a2i/a2u.h"
 #include "defines.h"
 #include "prototypes.h"
+#include "string/strcmp/streq.h"
 
 
 /*
@@ -53,7 +54,7 @@ getrange(const char *range,
 		return 0;  /* <long> */
 
 	case '-':
-		if ('\0' == *end)
+		if (streq(end, ""))
 			return 0;  /* <long>- */
 parse_max:
 		if (!isdigit((unsigned char) *end))

lib/limits.c

@@ -413,9 +413,9 @@ static int setup_user_limits (const char *uname)
 		}
 	}
 	(void) fclose (fil);
-	if (limits[0] == '\0') {
+	if (streq(limits, "")) {
 		/* no user specific limits */
-		if (deflimits[0] == '\0') {	/* no default limits */
+		if (streq(deflimits, "")) {	/* no default limits */
 			return 0;
 		}
 		strcpy (limits, deflimits);	/* use the default limits */

lib/list.c

@@ -209,7 +209,7 @@ comma_to_list(const char *comma)
 	 * Empty list is special - 0 members, not 1 empty member.  --marekm
 	 */
 
-	if ('\0' == *members) {
+	if (streq(members, "")) {
 		*array = NULL;
 		free (members);
 		return array;

lib/port.c

@@ -44,7 +44,7 @@ static int portcmp (const char *pattern, const char *port)
 		port++;
 	}
 
-	if (('\0' == *pattern) && ('\0' == *port)) {
+	if (streq(pattern, "") && streq(port, "")) {
 		return 0;
 	}
 	if (streq(orig, "SU"))
@@ -204,7 +204,7 @@ next:
 
 	cp = field;
 
-	if ('\0' == *cp) {
+	if (streq(cp, "")) {
 		port.pt_times = NULL;
 		return &port;
 	}

lib/prefix_flag.c

@@ -98,7 +98,7 @@ extern const char* process_prefix_flag (const char* short_opt, int argc, char **
 			exit (EXIT_FAILURE);
 		}
 
-		if (prefix[0] == '\0' || streq(prefix, "/"))
+		if (streq(prefix, "") || streq(prefix, "/"))
 			return ""; /* if prefix is "/" then we ignore the flag option */
 		/* should we prevent symbolic link from being used as a prefix? */
 

lib/pwauth.c

@@ -26,6 +26,7 @@
 #include "getdef.h"
 #include "string/memset/memzero.h"
 #include "string/sprintf/snprintf.h"
+#include "string/strcmp/streq.h"
 
 #ifdef SKEY
 #include <skey.h>
@@ -102,7 +103,7 @@ int pw_auth (const char *cipher,
 	 * matter.
 	 */
 
-	if ((NULL == cipher) || ('\0' == *cipher)) {
+	if ((NULL == cipher) || streq(cipher, "")) {
 		return 0;
 	}
 
@@ -169,7 +170,7 @@ int pw_auth (const char *cipher,
 	 * ...Re-prompt, with echo on.
 	 * -- AR 8/22/1999
 	 */
-	if ((0 != retval) && ('\0' == input[0]) && use_skey) {
+	if ((0 != retval) && streq(input, "") && use_skey) {
 		erase_pass(clear);
 		clear = agetpass(prompt);
 		input = (clear == NULL) ? "" : clear;

lib/salt.c

@@ -419,7 +419,7 @@ static /*@observer@*/const char *gensalt (size_t salt_size)
 	 * Prepare DES setting for crypt_gensalt(), if result
 	 * has not been filled with anything previously.
 	 */
-	if ('\0' == result[0]) {
+	if (streq(result, "")) {
 		/* Avoid -Wunused-but-set-variable. */
 		salt_len = GENSALT_SETTING_SIZE - 1;
 		rounds = 0;

lib/setupenv.c

@@ -28,6 +28,7 @@
 #include "shadowlog.h"
 #include "string/sprintf/xasprintf.h"
 #include "string/strchr/stpspn.h"
+#include "string/strcmp/streq.h"
 #include "string/strdup/xstrdup.h"
 #include "string/strtok/stpsep.h"
 
@@ -60,7 +61,7 @@ static void read_env_file (const char *filename)
 		cp = buf;
 		/* ignore whitespace and comments */
 		cp = stpspn(cp, " \t");
-		if (('\0' == *cp) || ('#' == *cp)) {
+		if (streq(cp, "") || ('#' == *cp)) {
 			continue;
 		}
 		/*
@@ -209,7 +210,7 @@ void setup_env (struct passwd *info)
 	 * Create the SHELL environmental variable and export it.
 	 */
 
-	if ((NULL == info->pw_shell) || ('\0' == *info->pw_shell)) {
+	if ((NULL == info->pw_shell) || streq(info->pw_shell, "")) {
 		free (info->pw_shell);
 		info->pw_shell = xstrdup (SHELL);
 	}

lib/sgetgrent.c

@@ -21,6 +21,7 @@
 #include "atoi/getnum.h"
 #include "defines.h"
 #include "prototypes.h"
+#include "string/strcmp/streq.h"
 #include "string/strtok/stpsep.h"
 
 
@@ -54,7 +55,7 @@ list(char *s)
 				return NULL;
 			}
 		}
-		if (!s || s[0] == '\0')
+		if (!s || streq(s, ""))
 			break;
 		members[i++] = strsep(&s, ",");
 	}
@@ -89,7 +90,7 @@ struct group *sgetgrent (const char *buf)
 	for (cp = grpbuf, i = 0; (i < NFIELDS) && (NULL != cp); i++)
 		grpfields[i] = strsep(&cp, ":");
 
-	if (i < NFIELDS || *grpfields[2] == '\0' || cp != NULL) {
+	if (i < NFIELDS || streq(grpfields[2], "") || cp != NULL) {
 		return NULL;
 	}
 	grent.gr_name = grpfields[0];

lib/sgetpwent.c

@@ -20,6 +20,7 @@
 #include "defines.h"
 #include "prototypes.h"
 #include "shadowlog_internal.h"
+#include "string/strcmp/streq.h"
 
 
 #define	NFIELDS	7
@@ -76,7 +77,11 @@ sgetpwent(const char *buf)
 	 * the entry is invalid.  Also, the UID and GID must be non-blank.
 	 */
 
-	if (i != NFIELDS || *fields[2] == '\0' || *fields[3] == '\0')
+	if (i != NFIELDS)
+		return NULL;
+	if (streq(fields[2], ""))
+		return NULL;
+	if (streq(fields[3], ""))
 		return NULL;
 
 	/*

lib/sgetspent.c

@@ -24,6 +24,7 @@
 #include "defines.h"
 #include "prototypes.h"
 #include "shadowlog_internal.h"
+#include "string/strcmp/streq.h"
 #include "string/strtok/stpsep.h"
 
 
@@ -85,7 +86,7 @@ sgetspent(const char *string)
 	 * incorrectly formatted number.
 	 */
 
-	if (fields[2][0] == '\0')
+	if (streq(fields[2], ""))
 		spwd.sp_lstchg = -1;
 	else if (a2sl(&spwd.sp_lstchg, fields[2], NULL, 0, 0, LONG_MAX) == -1)
 		return NULL;
@@ -94,7 +95,7 @@ sgetspent(const char *string)
 	 * Get the minimum period between password changes.
 	 */
 
-	if (fields[3][0] == '\0')
+	if (streq(fields[3], ""))
 		spwd.sp_min = -1;
 	else if (a2sl(&spwd.sp_min, fields[3], NULL, 0, 0, LONG_MAX) == -1)
 		return NULL;
@@ -103,7 +104,7 @@ sgetspent(const char *string)
 	 * Get the maximum number of days a password is valid.
 	 */
 
-	if (fields[4][0] == '\0')
+	if (streq(fields[4], ""))
 		spwd.sp_max = -1;
 	else if (a2sl(&spwd.sp_max, fields[4], NULL, 0, 0, LONG_MAX) == -1)
 		return NULL;
@@ -126,7 +127,7 @@ sgetspent(const char *string)
 	 * Get the number of days of password expiry warning.
 	 */
 
-	if (fields[5][0] == '\0')
+	if (streq(fields[5], ""))
 		spwd.sp_warn = -1;
 	else if (a2sl(&spwd.sp_warn, fields[5], NULL, 0, 0, LONG_MAX) == -1)
 		return NULL;
@@ -136,7 +137,7 @@ sgetspent(const char *string)
 	 * disabled.
 	 */
 
-	if (fields[6][0] == '\0')
+	if (streq(fields[6], ""))
 		spwd.sp_inact = -1;
 	else if (a2sl(&spwd.sp_inact, fields[6], NULL, 0, 0, LONG_MAX) == -1)
 		return NULL;
@@ -146,7 +147,7 @@ sgetspent(const char *string)
 	 * set to expire.
 	 */
 
-	if (fields[7][0] == '\0')
+	if (streq(fields[7], ""))
 		spwd.sp_expire = -1;
 	else if (a2sl(&spwd.sp_expire, fields[7], NULL, 0, 0, LONG_MAX) == -1)
 		return NULL;
@@ -156,7 +157,7 @@ sgetspent(const char *string)
 	 * to have anything other than a valid integer in it.
 	 */
 
-	if (fields[8][0] == '\0')
+	if (streq(fields[8], ""))
 		spwd.sp_flag = SHADOW_SP_FLAG_UNSET;
 	else if (str2ul(&spwd.sp_flag, fields[8]) == -1)
 		return NULL;

lib/sssd.c

@@ -1,7 +1,9 @@
 /* Author: Peter Vrabec <pvrabec@redhat.com> */
 
 #include <config.h>
+
 #ifdef USE_SSSD
+#include "sssd.h"
 
 #include <stdio.h>
 #include <sys/stat.h>
@@ -12,9 +14,8 @@
 #include "exitcodes.h"
 #include "defines.h"
 #include "prototypes.h"
-#include "sssd.h"
-
 #include "shadowlog_internal.h"
+#include "string/strcmp/streq.h"
 
 
 #define MSG_SSSD_FLUSH_CACHE_FAILED "%s: Failed to flush the sssd cache."
@@ -46,7 +47,7 @@ sssd_flush_cache(int dbflags)
 	if (dbflags & SSSD_DB_GROUP)
 		stpcpy(p, "G");
 
-	if (*p == '\0') {
+	if (streq(p, "")) {
 		/* Neither passwd nor group, nothing to do */
 		free(sss_cache_args);
 		return 0;

lib/strtoday.c

@@ -11,12 +11,11 @@
 
 #include <ctype.h>
 
-#ident "$Id$"
-
 #include "atoi/str2i/str2s.h"
 #include "getdate.h"
 #include "prototypes.h"
 #include "string/strchr/stpspn.h"
+#include "string/strcmp/streq.h"
 
 
 /*
@@ -44,7 +43,7 @@ long strtoday (const char *str)
 	 * which is not what we expect, unless you're a BOFH :-).
 	 * (useradd sets sp_expire = current date for new lusers)
 	 */
-	if ((NULL == str) || ('\0' == *str)) {
+	if ((NULL == str) || streq(str, "")) {
 		return -1;
 	}
 

lib/subordinateio.c

@@ -108,7 +108,13 @@ subordinate_parse(const char *line)
 	 * There must be exactly SUBID_NFIELDS colon separated fields or
 	 * the entry is invalid.  Also, fields must be non-blank.
 	 */
-	if (i != SUBID_NFIELDS || *fields[0] == '\0' || *fields[1] == '\0' || *fields[2] == '\0')
+	if (i != SUBID_NFIELDS)
+		return NULL;
+	if (streq(fields[0], ""))
+		return NULL;
+	if (streq(fields[1], ""))
+		return NULL;
+	if (streq(fields[2], ""))
 		return NULL;
 	range.owner = fields[0];
 	if (str2ul(&range.start, fields[1]) == -1)

lib/utmp.c

@@ -53,13 +53,13 @@ is_my_tty(const char tty[UTX_LINESIZE])
 		strcpy (full_tty, "/dev/");
 	strncat(full_tty, tty, UTX_LINESIZE);
 
-	if ('\0' == tmptty[0]) {
+	if (streq(tmptty, "")) {
 		const char *tname = ttyname (STDIN_FILENO);
 		if (NULL != tname)
 			STRTCPY(tmptty, tname);
 	}
 
-	if ('\0' == tmptty[0]) {
+	if (streq(tmptty, "")) {
 		(void) puts (_("Unable to determine your tty name."));
 		exit (EXIT_FAILURE);
 	}

lib/valid.c

@@ -42,8 +42,8 @@ bool valid (const char *password, const struct passwd *ent)
 	 * routine is meant to waste CPU time.
 	 */
 
-	if ((NULL != ent->pw_name) && ('\0' == ent->pw_passwd[0])) {
-		if ('\0' == password[0]) {
+	if ((NULL != ent->pw_name) && streq(ent->pw_passwd, "")) {
+		if (streq(password, "")) {
 			return true;	/* user entered nothing */
 		} else {
 			return false;	/* user entered something! */
@@ -54,7 +54,7 @@ bool valid (const char *password, const struct passwd *ent)
 	 * If there is no entry then we need a salt to use.
 	 */
 
-	if ((NULL == ent->pw_name) || ('\0' == ent->pw_passwd[0])) {
+	if ((NULL == ent->pw_name) || streq(ent->pw_passwd, "")) {
 		salt = "xx";
 	} else {
 		salt = ent->pw_passwd;

src/grpck.c

@@ -580,7 +580,8 @@ static void check_grp_file (int *errors, bool *changed)
 		 */
 		if (   (NULL != grp->gr_mem[0])
 		    && (NULL == grp->gr_mem[1])
-		    && ('\0' == grp->gr_mem[0][0])) {
+		    && streq(grp->gr_mem[0], ""))
+		{
 			grp->gr_mem[0] = NULL;
 		}
 

src/login.c

@@ -661,7 +661,7 @@ int main (int argc, char **argv)
 		/* if we didn't get a user on the command line,
 		   set it to NULL */
 		get_pam_user (&pam_user);
-		if ((NULL != pam_user) && ('\0' == pam_user[0])) {
+		if ((NULL != pam_user) && streq(pam_user, "")) {
 			retcode = pam_set_item (pamh, PAM_USER, NULL);
 			PAM_FAIL_CHECK;
 		}
@@ -838,7 +838,7 @@ int main (int argc, char **argv)
 			username = XMALLOC(max_size, char);
 			login_prompt(username, max_size);
 
-			if ('\0' == username[0]) {
+			if (streq(username, "")) {
 				/* Prompt for a new login */
 				free (username);
 				username = NULL;
@@ -963,7 +963,7 @@ int main (int argc, char **argv)
 		 * guys won't see that the passwordless account exists at
 		 * all).  --marekm
 		 */
-		if (user_passwd[0] == '\0') {
+		if (streq(user_passwd, "")) {
 			pw_auth ("!", username, reason, NULL);
 		}
 

src/login_nopam.c

@@ -29,7 +29,6 @@
 #ifndef USE_PAM
 #ident "$Id$"
 
-#include "prototypes.h"
     /*
      * This module implements a simple but effective form of login access
      * control based on login names and on host (or domain) names, internet
@@ -38,27 +37,29 @@
      *
      * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
      */
-#include <sys/types.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <syslog.h>
+#include <arpa/inet.h>		/* for inet_ntoa() */
 #include <ctype.h>
-#include <netdb.h>
+#include <errno.h>
 #include <grp.h>
+#include <netdb.h>
+#include <netinet/in.h>
 #ifdef PRIMARY_GROUP_MATCH
 #include <pwd.h>
 #endif
-#include <errno.h>
-#include <string.h>
-#include <unistd.h>
+#include <stddef.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/param.h>
 #include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>		/* for inet_ntoa() */
+#include <sys/types.h>
+#include <syslog.h>
+#include <unistd.h>
 
+#include "prototypes.h"
 #include "sizeof.h"
 #include "string/strchr/strrspn.h"
+#include "string/strcmp/streq.h"
 #include "string/strtok/stpsep.h"
 
 
@@ -110,7 +111,7 @@ login_access(const char *user, const char *from)
 				continue;	/* comment line */
 			}
 			stpcpy(strrspn(line, " \t"), "");
-			if (line[0] == '\0') {	/* skip blank lines */
+			if (streq(line, "")) {	/* skip blank lines */
 				continue;
 			}
 			p = line;
@@ -182,7 +183,7 @@ static char *myhostname (void)
 {
 	static char name[MAXHOSTNAMELEN + 1] = "";
 
-	if (name[0] == '\0') {
+	if (streq(name, "")) {
 		gethostname (name, sizeof (name));
 		stpcpy(&name[MAXHOSTNAMELEN], "");
 	}

src/newgrp.c

@@ -150,7 +150,7 @@ static void check_perms (const struct group *grp,
 		spw_free (spwd);
 	}
 
-	if ((pwd->pw_passwd[0] == '\0') && (grp->gr_passwd[0] != '\0')) {
+	if (streq(pwd->pw_passwd, "") && (grp->gr_passwd[0] != '\0')) {
 		needspasswd = true;
 	}
 
@@ -188,8 +188,8 @@ static void check_perms (const struct group *grp,
 			goto failure;
 		}
 
-		if (grp->gr_passwd[0] == '\0' ||
-		    !streq(cpasswd, grp->gr_passwd)) {
+		if (streq(grp->gr_passwd, "") ||
+		    !streq(grp->gr_passwd, cpasswd)) {
 #ifdef WITH_AUDIT
 			SNPRINTF(audit_buf, "authentication new-gid=%lu",
 			         (unsigned long) grp->gr_gid);

src/passwd.c

@@ -441,7 +441,7 @@ static /*@observer@*/const char *pw_status (const char *pass)
 	if (*pass == '*' || *pass == '!') {
 		return "L";
 	}
-	if (*pass == '\0') {
+	if (streq(pass, "")) {
 		return "NP";
 	}
 	return "P";

src/su.c

@@ -862,7 +862,7 @@ static void process_flags (int argc, char **argv)
 	if (optind < argc) {
 		STRTCPY(name, argv[optind++]);	/* use this login id */
 	}
-	if ('\0' == name[0]) {		/* use default user */
+	if (streq(name, "")) {		/* use default user */
 		struct passwd *root_pw = getpwnam ("root");
 		if ((NULL != root_pw) && (0 == root_pw->pw_uid)) {
 			(void) strcpy (name, "root");
@@ -1080,7 +1080,7 @@ int main (int argc, char **argv)
 	/*
 	 * Set the default shell.
 	 */
-	if ((NULL == shellstr) || ('\0' == shellstr[0])) {
+	if ((NULL == shellstr) || streq(shellstr, "")) {
 		shellstr = SHELL;
 	}
 

src/suauth.c

@@ -86,7 +86,7 @@ check_su_auth(const char *actual_id, const char *wanted_id, bool su_to_root)
 		stpcpy(strrspn(temp, " \t"), "");
 
 		p = stpspn(temp, " \t");
-		if (*p == '#' || *p == '\0')
+		if (*p == '#' || streq(p, ""))
 			continue;
 
 		to_users = strsep(&p, ":");

src/sulogin.c

@@ -27,6 +27,7 @@
 /*@-exitarg@*/
 #include "exitcodes.h"
 #include "shadowlog.h"
+#include "string/strcmp/streq.h"
 #include "string/strdup/xstrdup.h"
 
 
@@ -153,7 +154,7 @@ main(int argc, char *argv[])
 		 * it will work with standard getpass() (no NULL on EOF).
 		 * --marekm
 		 */
-		if ((NULL == pass) || ('\0' == *pass)) {
+		if ((NULL == pass) || streq(pass, "")) {
 			erase_pass (pass);
 			(void) puts ("");
 #ifdef	TELINIT

src/useradd.c

@@ -439,7 +439,7 @@ get_defaults(void)
 		 * Default Skeleton information
 		 */
 		else if (streq(buf, DSKEL)) {
-			if ('\0' == *ccp)
+			if (streq(ccp, ""))
 				ccp = SKEL_DIR;
 
 			if (prefix[0]) {
@@ -456,7 +456,7 @@ get_defaults(void)
 		 * Default Usr Skeleton information
 		 */
 		else if (streq(buf, DUSRSKEL)) {
-			if ('\0' == *ccp)
+			if (streq(ccp, ""))
 				ccp = USRSKELDIR;
 
 			if (prefix[0]) {
@@ -472,7 +472,7 @@ get_defaults(void)
 		 * Create by default user mail spool or not ?
 		 */
 		else if (streq(buf, DCREATE_MAIL_SPOOL)) {
-			if (*ccp == '\0')
+			if (streq(ccp, ""))
 				ccp = "no";
 
 			def_create_mail_spool = xstrdup(ccp);
@@ -482,7 +482,7 @@ get_defaults(void)
 		 * By default do we add the user to the lastlog and faillog databases ?
 		 */
 		else if (streq(buf, DLOG_INIT)) {
-			if (*ccp == '\0')
+			if (streq(ccp, ""))
 				ccp = def_log_init;
 
 			def_log_init = xstrdup(ccp);
@@ -770,7 +770,7 @@ static int get_groups (char *list)
 		user_groups[i++] = NULL;
 	}
 
-	if ('\0' == *list) {
+	if (streq(list, "")) {
 		return 0;
 	}
 

src/userdel.c

@@ -1131,7 +1131,7 @@ int main (int argc, char **argv)
 	 * Note: This is a best effort basis. The user may log in between,
 	 * a cron job may be started on her behalf, etc.
 	 */
-	if ((prefix[0] == '\0') && !Rflg && user_busy (user_name, user_id) != 0) {
+	if (streq(prefix, "") && !Rflg && user_busy(user_name, user_id) != 0) {
 		if (!fflg) {
 #ifdef WITH_AUDIT
 			audit_logger (AUDIT_DEL_USER, Prog,
@@ -1264,7 +1264,7 @@ int main (int argc, char **argv)
 	 * Cancel any crontabs or at jobs. Have to do this before we remove
 	 * the entry from /etc/passwd.
 	 */
-	if (prefix[0] == '\0')
+	if (streq(prefix, ""))
 		user_cancel (user_name);
 	close_files ();
 

src/usermod.c

@@ -227,7 +227,7 @@ static int get_groups (char *list)
 	 */
 	user_groups[0] = NULL;
 
-	if ('\0' == *list) {
+	if (streq(list, "")) {
 		return 0;
 	}
 
@@ -2186,7 +2186,7 @@ int main (int argc, char **argv)
 	 * be changed while the user is logged in.
 	 * Note: no need to check if a prefix is specified...
 	 */
-	if ( (prefix[0] == '\0') &&  (uflg || lflg || dflg
+	if (streq(prefix, "") && (uflg || lflg || dflg
 #ifdef ENABLE_SUBIDS
 	        || Vflg || Wflg
 #endif				/* ENABLE_SUBIDS */