NeoMutt  2022-04-29-247-gc6aae8
Teaching an old dog new tricks
DOXYGEN
filter.h File Reference

Pass files through external commands (filters) More...

#include <stdio.h>
#include <unistd.h>
+ Include dependency graph for filter.h:
+ This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Macros

#define EXEC_SHELL   "/bin/sh"
 

Functions

pid_t filter_create (const char *cmd, FILE **fp_in, FILE **fp_out, FILE **fp_err)
 Set up filter program. More...
 
pid_t filter_create_fd (const char *cmd, FILE **fp_in, FILE **fp_out, FILE **fp_err, int fdin, int fdout, int fderr)
 Run a command on a pipe (optionally connect stdin/stdout) More...
 
int filter_wait (pid_t pid)
 Wait for the exit of a process and return its status. More...
 

Detailed Description

Pass files through external commands (filters)

Authors

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Definition in file filter.h.

Macro Definition Documentation

◆ EXEC_SHELL

#define EXEC_SHELL   "/bin/sh"

Definition at line 27 of file filter.h.

Function Documentation

◆ filter_create()

pid_t filter_create ( const char *  cmd,
FILE **  fp_in,
FILE **  fp_out,
FILE **  fp_err 
)

Set up filter program.

Parameters
[in]cmdCommand string
[out]fp_inFILE pointer of stdin
[out]fp_outFILE pointer of stdout
[out]fp_errFILE pointer of stderr
Return values
numPID of filter

Definition at line 206 of file filter.c.

207{
208 return filter_create_fd(cmd, fp_in, fp_out, fp_err, -1, -1, -1);
209}
pid_t filter_create_fd(const char *cmd, FILE **fp_in, FILE **fp_out, FILE **fp_err, int fdin, int fdout, int fderr)
Run a command on a pipe (optionally connect stdin/stdout)
Definition: filter.c:61
+ Here is the call graph for this function:
+ Here is the caller graph for this function:

◆ filter_create_fd()

pid_t filter_create_fd ( const char *  cmd,
FILE **  fp_in,
FILE **  fp_out,
FILE **  fp_err,
int  fdin,
int  fdout,
int  fderr 
)

Run a command on a pipe (optionally connect stdin/stdout)

Parameters
[in]cmdCommand line to invoke using sh -c
[out]fp_inFile stream pointing to stdin for the command process, can be NULL
[out]fp_outFile stream pointing to stdout for the command process, can be NULL
[out]fp_errFile stream pointing to stderr for the command process, can be NULL
[in]fdinIf in is NULL and fdin is not -1 then fdin will be used as stdin for the command process
[in]fdoutIf out is NULL and fdout is not -1 then fdout will be used as stdout for the command process
[in]fderrIf error is NULL and fderr is not -1 then fderr will be used as stderr for the command process
Return values
numPID of the created process
-1Error creating pipes or forking

This function provides multiple mechanisms to handle IO sharing for the command process. File streams are prioritized over file descriptors if present.

filter_create_fd(commandline, NULL, NULL, NULL, -1, -1, -1);

Additionally, fp_in, fp_out, and fp_err will point to FILE* streams representing the processes stdin, stdout, and stderr.

Definition at line 61 of file filter.c.

63{
64 int pin[2], pout[2], perr[2], pid;
65
66 if (fp_in)
67 {
68 *fp_in = NULL;
69 if (pipe(pin) == -1)
70 return -1;
71 }
72
73 if (fp_out)
74 {
75 *fp_out = NULL;
76 if (pipe(pout) == -1)
77 {
78 if (fp_in)
79 {
80 close(pin[0]);
81 close(pin[1]);
82 }
83 return -1;
84 }
85 }
86
87 if (fp_err)
88 {
89 *fp_err = NULL;
90 if (pipe(perr) == -1)
91 {
92 if (fp_in)
93 {
94 close(pin[0]);
95 close(pin[1]);
96 }
97 if (fp_out)
98 {
99 close(pout[0]);
100 close(pout[1]);
101 }
102 return -1;
103 }
104 }
105
107
108 pid = fork();
109 if (pid == 0)
110 {
112
113 if (fp_in)
114 {
115 close(pin[1]);
116 dup2(pin[0], 0);
117 close(pin[0]);
118 }
119 else if (fdin != -1)
120 {
121 dup2(fdin, 0);
122 close(fdin);
123 }
124
125 if (fp_out)
126 {
127 close(pout[0]);
128 dup2(pout[1], 1);
129 close(pout[1]);
130 }
131 else if (fdout != -1)
132 {
133 dup2(fdout, 1);
134 close(fdout);
135 }
136
137 if (fp_err)
138 {
139 close(perr[0]);
140 dup2(perr[1], 2);
141 close(perr[1]);
142 }
143 else if (fderr != -1)
144 {
145 dup2(fderr, 2);
146 close(fderr);
147 }
148
149 execle(EXEC_SHELL, "sh", "-c", cmd, NULL, mutt_envlist_getlist());
150 _exit(127);
151 }
152 else if (pid == -1)
153 {
155
156 if (fp_in)
157 {
158 close(pin[0]);
159 close(pin[1]);
160 }
161
162 if (fp_out)
163 {
164 close(pout[0]);
165 close(pout[1]);
166 }
167
168 if (fp_err)
169 {
170 close(perr[0]);
171 close(perr[1]);
172 }
173
174 return -1;
175 }
176
177 if (fp_out)
178 {
179 close(pout[1]);
180 *fp_out = fdopen(pout[0], "r");
181 }
182
183 if (fp_in)
184 {
185 close(pin[0]);
186 *fp_in = fdopen(pin[1], "w");
187 }
188
189 if (fp_err)
190 {
191 close(perr[1]);
192 *fp_err = fdopen(perr[0], "r");
193 }
194
195 return pid;
196}
char ** mutt_envlist_getlist(void)
Get the private environment.
Definition: envlist.c:169
#define EXEC_SHELL
Definition: filter.h:27
void mutt_sig_block_system(void)
Block signals before calling exec()
Definition: signal.c:183
void mutt_sig_unblock_system(bool restore)
Restore previously blocked signals.
Definition: signal.c:207
+ Here is the call graph for this function:
+ Here is the caller graph for this function:

◆ filter_wait()

int filter_wait ( pid_t  pid)

Wait for the exit of a process and return its status.

Parameters
pidProcess id of the process to wait for
Return values
numExit status of the process identified by pid
-1Error

Definition at line 217 of file filter.c.

218{
219 int rc = 0;
220
221 waitpid(pid, &rc, 0);
223 rc = WIFEXITED(rc) ? WEXITSTATUS(rc) : -1;
224
225 return rc;
226}
+ Here is the call graph for this function:
+ Here is the caller graph for this function: