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 */ 221