1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2010 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * Copyright 2017 Joyent, Inc.
29 */
30
31 #ifndef _OFMT_H
32 #define _OFMT_H
33
34 /*
35 * Data structures and routines for printing output.
36 *
37 * All output is assumed to be in a columnar format, where each column
38 * represents a field to be printed out. Multiple fields in parsable output
39 * are separated by ':', with the ':' character itself escaped by a \
40 * (e.g., IPv6 addresses may be printed as "fe80\:\:1"); single field output
41 * is printed as-is.
42 * In multiline mode, every [field,value] pair is printed in a line of
43 * its own, thus: "field: value".
44 *
45 * The caller must open a handle for each set of fields to be printed by
46 * invoking ofmt_open(). The invocation to ofmt_open must provide the list of
47 * supported fields, along with formatting information (e.g., field width), and
48 * a pointer to a callback function that can provide a string representation of
49 * the value to be printed out. The set of supported fields must be a NULL
50 * terminated array of type ofmt_field_t *ofields[]. The contents of the
51 * ofmt_field_t structure are used to construct the string that is emitted by
52 * ofmt_print(), and the interpretation of these contents is described with the
53 * semantics of ofmt_print() below.
54 *
55 * In addition, the call to ofmt_open() should provide a comma-separated
56 * list of the fields, char *fields_str, that have been selected for output
57 * (typically the string passed to -o in the command-line). The caller may
58 * also specify machine-parsable mode by specifying OFMT_PARSABLE in the oflags
59 * argument. Specifying a null or empty fields_str in the machine-parsable mode
60 * will result in a returned error value of OFMT_EPARSENONE. An attempt to
61 * create a handle in machine-parsable mode with the fields_str set to "all"
62 * will result in a returned error value of OFMT_EPARSEALL. In human-friendly
63 * (non machine-parsable) mode, a NULL fields_str, or a value of "all" for
64 * fields_str, is treated as a request to print all allowable fields that fit
65 * other applicable constraints.
66 * To achieve multiline mode, OFMT_MULTILINE needs to be specified in oflags.
67 * Specifying both OFMT_MULTILINE and OFMT_PARSABLE will result in
68 * OFMT_EPARSEMULTI.
69 *
70 * Thus a typical invocation to open the ofmt_handle would be:
71 *
72 * ofmt_handle_t ofmt;
73 * ofmt_status_t ofmt_err;
74 *
75 * ofmt_err = ofmt_open(fields_str, ofields, oflags, maxcols, &ofmt);
76 *
77 * where ofields is an array of the form:
78 *
79 * static ofmt_field_t ofields[] = {
80 * {<name>, <field width>, <id>, <callback> },
81 * :
82 * {<name>, <field width>, <id>, <callback> },
83 * {NULL, 0, 0, NULL}}
84 *
85 * <callback> is the application-specified function that provides a string
86 * representation of the value to be printed for the field. The calling
87 * application may provide unique values of <id> that will be passed back to
88 * <callback>, allowing a single <callback> to be shared between multiple
89 * fields in ofields[] with the value of <id> identifying the field that
90 * triggers the callback.
91 *
92 * If successful, ofmt_open() will return OFMT_SUCCESS, with a non-null
93 * ofmt_handle. The function returns a failure code otherwise, and more
94 * information about the type of failure can be obtained by calling
95 * ofmt_strerror()
96 *
97 * In order to print a row of output, the calling application should invoke
98 *
99 * ofmt_print(ofmt_handle, cbarg);
100 *
101 * where 'cbarg' points at the arguments to be passed to the <callback>
102 * function for each column in the row. The call to ofmt_print() will then
103 * result in the <callback> function of each selected field from ofields[]
104 * invoked with cbarg embedded in the ofmt_arg as
105 *
106 * (*callback)(ofmt_arg_t *ofmt_arg, char *buf, uint_t bufsize)
107 *
108 * Columns selected for output are identified by a match between the of_name
109 * value in the ofmt_field_t and the fields_str requested. For each selected
110 * column, the callback function (*of_cb)() is invoked, and is passed the of_id
111 * value from the ofmt_field_t structure for the field.
112 *
113 * The interpretation of the of_id field is completely private to the caller,
114 * and can be optionally used by the callback function as a cookie
115 * to identify the field being printed when a single callback function is
116 * shared between multiple ofmt_field_t entries.
117 *
118 * The callback function should fill `buf' with the string to be printed for
119 * the field using the data in cbarg.
120 *
121 * The calling application should invoke ofmt_close(ofmt_handle) to free up any
122 * resources allocated for the handle after all printing is completed.
123 *
124 * The printing library computes the current size of the output window when the
125 * handle is first created. If the caller wishes to adjust the window size
126 * after the handle has been created (e.g., on the reception of SIGWINCH by the
127 * caller), the function ofmt_update_winsize(handle) may be called.
128 */
129
130 #include <sys/types.h>
131
132 #ifdef __cplusplus
133 extern "C" {
134 #endif
135
136 /*
137 * Recommended buffer size for buffers passed, for example, to ofmt_strerror().
138 */
139 #define OFMT_BUFSIZE 256
140
141 typedef enum {
142 OFMT_SUCCESS = 0,
143 OFMT_ENOMEM, /* out of memory */
144 OFMT_EBADFIELDS, /* one or more bad fields with good fields */
145 OFMT_ENOFIELDS, /* no valid output fields */
146 OFMT_EPARSEALL, /* 'all' invalid in parsable mode */
147 OFMT_EPARSENONE, /* output fields missing in parsable mode */
148 OFMT_EPARSEWRAP, /* parsable mode incompatible with wrap mode */
149 OFMT_ENOTEMPLATE, /* no template provided for fields */
150 OFMT_EPARSEMULTI /* parsable and multiline don't mix */
151 } ofmt_status_t;
152
153 /*
154 * The callback function for each field is invoked with a pointer to the
155 * ofmt_arg_t structure that contains the <id> registered by the application
156 * for that field, and the cbarg used by the application when invoking
157 * ofmt_output().
158 */
159 typedef struct ofmt_arg_s {
160 uint_t ofmt_id;
161 uint_t ofmt_width;
162 uint_t ofmt_index;
163 void *ofmt_cbarg;
164 } ofmt_arg_t;
165
166 /*
167 * ofmt callback function that provides a string representation of the value to
168 * be printed for the field.
169 */
170 typedef boolean_t ofmt_cb_t(ofmt_arg_t *, char *, uint_t);
171 typedef struct ofmt_field_s {
172 char *of_name; /* column name */
173 uint_t of_width; /* output column width */
174 uint_t of_id; /* implementation specific cookie */
175 ofmt_cb_t *of_cb; /* callback function defined by caller */
176 } ofmt_field_t;
177
178 /*
179 * ofmt_open() must be called to create the ofmt_handle_t; Resources allocated
180 * for the handle are freed by ofmt_close();
181 */
182 typedef struct ofmt_state_s *ofmt_handle_t;
183 extern ofmt_status_t ofmt_open(const char *, const ofmt_field_t *, uint_t,
184 uint_t, ofmt_handle_t *);
185
186 #define OFMT_PARSABLE 0x00000001 /* machine parsable mode */
187 #define OFMT_WRAP 0x00000002 /* wrap output if field width is exceeded */
188 #define OFMT_MULTILINE 0x00000004 /* "long" output: "name: value" lines */
189 #define OFMT_RIGHTJUST 0x00000008 /* right justified output */
190
191 /*
192 * ofmt_close() must be called to free resources associated
193 * with the ofmt_handle_t
194 */
195 extern void ofmt_close(ofmt_handle_t);
196
197 /*
198 * ofmt_print() emits one row of output
199 */
200 extern void ofmt_print(ofmt_handle_t, void *);
201
202 /*
203 * ofmt_update_winsize() updates the window size information for ofmt_handle_t
204 */
205 extern void ofmt_update_winsize(ofmt_handle_t);
206
207 /*
208 * ofmt_strerror() provides error diagnostics in the buffer that it is passed.
209 */
210 extern char *ofmt_strerror(ofmt_handle_t, ofmt_status_t, char *, uint_t);
211
212 extern void ofmt_check(ofmt_status_t oferr, boolean_t parsable,
213 ofmt_handle_t ofmt,
214 void (*die)(const char *, ...), void (*warn)(const char *, ...));
215
216 #ifdef __cplusplus
217 }
218 #endif
219
220 #endif /* _OFMT_H */