zdev: implement --shell command line switch

Fix issue in the lszdev command where column names if using the --pairs
command line switch can contain characters that are not allowed to be
used as variable names in a shell environment.

Replace bad characters in column names by an underscore if the --shell
command line switch is specified along with the --pairs switch.

The additional --shell switch mimics what is already available in the
lsblk command and thus it shall be used along with the --pairs switch.

Signed-off-by: Daniel S. Haischt <modean@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>

zdev/include/table.h

@@ -66,7 +66,7 @@ typedef char *(*table_value_cb_t)(void *item, int id, const char *heading,
 struct column *table_get_column(struct column *, const char *);
 exit_code_t table_print(struct column *, table_value_cb_t, void *,
 			struct util_list *, struct util_list *, int, int, int,
-			int);
+			int, int);
 exit_code_t table_check_columns(struct column *, struct util_list *);
 void table_print_columns(struct column *, struct util_list *, int, int);
 void table_set_default(struct column *, int, int);

zdev/include/table_attribs.h

@@ -23,7 +23,7 @@ struct table_attrib {
 };
 
 struct table_attrib *table_attrib_new(struct subtype *, struct attrib *);
-void table_attribs_show(struct util_list *, int, int, struct devtype *);
+void table_attribs_show(struct util_list *, int, int, int, struct devtype *);
 void table_attribs_show_details(struct util_list *, struct devtype *);
 
 #endif /* TABLE_ATTRIBS_H */

zdev/man/lszdev.8

@@ -423,6 +423,17 @@ with the name of the corresponding column. Values are enclosed in double
 quotation marks. Any quotation marks or slashes in the value string are
 escaped by placing a slash in front of it.
 .PP
+
+.OD shell "" ""
+Produces KEY="VALUE" format usable as shell variables.
+
+You can use this option together with the --pairs option to generate
+output that is suitable to be sourced in a shell environment. This
+option generates similar output as it would be provided by the --pairs
+option but it would take care of replacing any character of a column
+name that would not be appropriate to be used as part of a shell
+variable name by an underscore.
+.PP
 .
 .OD persistent "p" ""
 List information from the persistent configuration only.

zdev/src/chzdev.c

@@ -2532,7 +2532,7 @@ static exit_code_t do_list_attribs(struct options *opts)
 	remove_duplicate_attribs(attribs, devtype_count_subtypes(dt));
 
 	if (attribs) {
-		table_attribs_show(attribs, 1, 0, dt);
+		table_attribs_show(attribs, 1, 0, 0, dt);
 		ptrlist_free(attribs, 1);
 	} else
 		rc = EXIT_ATTRIB_NOT_FOUND;

zdev/src/lszdev.c

@@ -70,6 +70,7 @@ struct options {
 	unsigned int no_headings:1;
 	struct util_list *base;		/* List of struct strlist_node */
 	unsigned int pairs:1;
+	unsigned int shell:1;
 	unsigned int verbose:1;
 	unsigned int quiet:1;
 	unsigned int site_id;
@@ -106,6 +107,7 @@ enum {
 	OPT_VERBOSE		= 'V',
 	OPT_QUIET		= 'q',
 	OPT_PAIRS		= 'P',
+	OPT_SHELL		= (OPT_ANONYMOUS_BASE+__COUNTER__),
 	OPT_AUTO_CONF		= (OPT_ANONYMOUS_BASE+__COUNTER__),
 	OPT_SITE		= 's',
 };
@@ -167,6 +169,7 @@ static const struct option opt_list[] = {
 	{ "no-headings",	no_argument,	NULL, OPT_NO_HEADINGS },
 	{ "base",		required_argument, NULL, OPT_BASE },
 	{ "pairs",		no_argument,	NULL, OPT_PAIRS },
+	{ "shell",              no_argument,    NULL, OPT_SHELL },
 	{ "verbose",		no_argument,	NULL, OPT_VERBOSE },
 	{ "quiet",		no_argument,	NULL, OPT_QUIET },
 	{ "site",		required_argument, NULL, OPT_SITE },
@@ -699,6 +702,11 @@ static exit_code_t parse_options(struct options *opts, int argc, char *argv[])
 			opts->pairs = 1;
 			break;
 
+		case OPT_SHELL:
+			/* --shell */
+			opts->shell = 1;
+			break;
+
 		case OPT_VERBOSE:
 			/* --verbose */
 			opts->verbose = 1;
@@ -761,6 +769,13 @@ static exit_code_t parse_options(struct options *opts, int argc, char *argv[])
 	if (rc)
 		goto out;
 
+	/* check whether --pairs and --columns is used */
+	if (opts->shell == 1 && (opts->pairs != 1 || util_list_is_empty(opts->columns))) {
+		syntax("'--shell' must be used together with "
+		       "'--pairs' and '--columns'\n");
+		return EXIT_USAGE_ERROR;
+	}
+
 	/* Determine configuration set. */
 	if (!opts->active && !opts->persistent && !opts->auto_conf) {
 		/* Default display targets are active + persistent - note that
@@ -1209,7 +1224,7 @@ static exit_code_t do_list_devices(struct options *opts)
 	/* Display table. */
 	rc = table_print(dev_table, dev_table_get_value, opts, items,
 			 opts->columns, !opts->no_headings, opts->pairs, 0,
-			 util_list_is_empty(opts->columns));
+			 util_list_is_empty(opts->columns), opts->shell);
 	ptrlist_free(items, 0);
 
 	return rc;
@@ -1443,7 +1458,7 @@ static void settings_table_print(struct setting_list *active,
 	data.pairs = opts->pairs;
 
 	table_print(settings_table, settings_table_get_value, &data, items,
-		    NULL, 1, opts->pairs, ind, 0);
+		    NULL, 1, opts->pairs, ind, 0, opts->shell);
 
 out:
 	ptrlist_free(items, 1);

zdev/src/lszdev_usage.txt

@@ -41,6 +41,7 @@ OPTIONS
   -n, --no-headings      Do not print column headings
       --base PATH        Use PATH as base for accessing files
       --pairs            Produce output in KEY="VALUE" format
+      --shell            Produces KEY="VALUE" format usable as shell variables
       --auto-conf        Only show auto-configuration data
   -s, --site ID          Only show data configured for the specified site
   -V, --verbose          Print additional run-time information

zdev/src/table.c

@@ -7,6 +7,7 @@
  * it under the terms of the MIT license. See LICENSE for details.
  */
 
+#include <ctype.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -116,6 +117,40 @@ static struct cell *cells_get_default(struct column *columns)
 	return cells;
 }
 
+bool is_shell_char(const char c)
+{
+	/* check whether character is alphabetic */
+	if (tolower(c) >= 'a' && tolower(c) <= 'z')
+		return true;
+	if (isdigit(c) || c == '_')
+		return true;
+	return false;
+}
+
+/* replaces bad characters that won't work if using them
+ * as part of variable names in a shell environment
+ */
+char *replace_bad_chars(const char *value)
+{
+	int i;
+	char *copy, c;
+
+	/* remove bad characters and replace them by an underscore */
+	copy = misc_strdup(value);
+	for (i = 0; (c = value[i]); i++) {
+		/*
+		 * check whether character is alphabetic,
+		 * first character of an env var can't be a digit
+		 */
+		if (!is_shell_char(c) || (i == 0 && isdigit(c)))
+			c = '_';
+		/* copy character into string copy */
+		copy[i] = c;
+	}
+
+	return copy;
+}
+
 /* Return a newly allocated array of struct cells containing a struct cell for
  * each column definition whose name was specified in strlist @names. */
 static struct cell *cells_get(struct column *columns, struct util_list *names)
@@ -320,17 +355,23 @@ do_print:
 }
 
 /* Print all cells in a row in pairs format. */
-static void print_row_pairs(struct cell *cells)
+static void print_row_pairs(struct cell *cells, int shell)
 {
 	int i;
 	struct cell *c;
 	char *val;
+	char *heading;
 
 	for (i = 0; cells[i].heading; i++) {
 		c = &cells[i];
 		val = quote_str(c->value ? c->value : "", 1);
-		printf("%s%s=%s", i > 0 ? " " : "", c->heading, val);
+		if (shell)
+			heading = replace_bad_chars(c->heading);
+		else
+			heading = misc_strdup(c->heading);
+		printf("%s%s=%s", i > 0 ? " " : "", heading, val);
 		free(val);
+		free(heading);
 	}
 	printf("\n");
 }
@@ -342,7 +383,7 @@ static void print_row_pairs(struct cell *cells)
 exit_code_t table_print(struct column *columns, table_value_cb_t get_value_cb,
 			void *data, struct util_list *items,
 			struct util_list *names, int heading, int pairs,
-			int indent, int wrap)
+			int indent, int wrap, int shell)
 {
 	struct cell *cells;
 	struct ptrlist_node *p;
@@ -372,7 +413,7 @@ exit_code_t table_print(struct column *columns, table_value_cb_t get_value_cb,
 	util_list_iterate(items, p) {
 		cells_get_values(cells, p->ptr, get_value_cb, data);
 		if (pairs)
-			print_row_pairs(cells);
+			print_row_pairs(cells, shell);
 		else
 			print_row(cells, space, indent, wrap);
 	}
@@ -434,7 +475,7 @@ void table_print_columns(struct column *columns, struct util_list *names,
 	for (i = 0; columns[i].name; i++)
 		ptrlist_add(items, &columns[i]);
 	table_print(columns_table, columns_table_get_value, NULL, items, names,
-		    heading, pairs, 0, 0);
+		    heading, pairs, 0, 0, 0);
 	ptrlist_free(items, 0);
 }
 

zdev/src/table_attribs.c

@@ -115,7 +115,7 @@ void print_type(struct devtype *dt, struct subtype *st, bool multiple)
 
 /* Display table of attributes. */
 void table_attribs_show(struct util_list *attribs, int headings, int pairs,
-			struct devtype *dt)
+			int shell, struct devtype *dt)
 {
 	struct util_list *subtypes, *subattribs;
 	struct ptrlist_node *p;
@@ -145,7 +145,7 @@ void table_attribs_show(struct util_list *attribs, int headings, int pairs,
 		print_type(dt, st, multiple);
 
 		table_print(table_attribs, table_attribs_get_value, st,
-			    subattribs, NULL, headings, pairs, indent, 0);
+			    subattribs, NULL, headings, pairs, shell, indent, 0);
 
 		ptrlist_free(subattribs, 0);
 	}

zdev/src/table_types.c

@@ -83,7 +83,7 @@ exit_code_t table_types_show(struct util_list *columns, int headings, int pairs)
 
 	items = table_types_build();
 	rc = table_print(table_types, table_types_get_value, NULL,
-			 items, columns, headings, pairs, 0, 0);
+			 items, columns, headings, pairs, 0, 0, 0);
 	ptrlist_free(items, 1);
 
 	return rc;