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Diffstat (limited to 'nuttx/sched/env_setenv.c')
| -rw-r--r-- | nuttx/sched/env_setenv.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/nuttx/sched/env_setenv.c b/nuttx/sched/env_setenv.c new file mode 100644 index 000000000..c186241ef --- /dev/null +++ b/nuttx/sched/env_setenv.c @@ -0,0 +1,208 @@ +/**************************************************************************** + * sched/env_setenv.c + * + * Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#ifndef CONFIG_DISABLE_ENVIRON + +#include <stdio.h> +#include <stdlib.h> +#include <sched.h> +#include <string.h> +#include <errno.h> + +#include <nuttx/kmalloc.h> + +#include "os_internal.h" +#include "env_internal.h" + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: setenv + * + * Description: + * The setenv() function adds the variable name to the environment with the + * specified 'value' if the varialbe 'name" does not exist. If the 'name' + * does exist in the environment, then its value is changed to 'value' if + * 'overwrite' is non-zero; if 'overwrite' is zero, then the value of name + * unaltered. + * + * Parameters: + * name - The name of the variable to change + * value - The new value of the variable + * overwrite - Replace any existing value if non-zero. + * + * Return Value: + * Zero on success + * + * Assumptions: + * Not called from an interrupt handler + * + ****************************************************************************/ + +int setenv(const char *name, const char *value, int overwrite) +{ + FAR _TCB *rtcb; + FAR environ_t *envp; + FAR char *pvar; + int varlen; + int ret = OK; + + /* Verify input parameter */ + + if (!name) + { + ret = EINVAL; + goto errout; + } + + /* if no value is provided, then this is the same as unsetenv (unless + * overwrite is false) + */ + + if (!value || *value == '\0') + { + /* If overwite is set then this is the same as unsetenv */ + + if (overwrite) + { + return unsetenv(name); + } + else + { + /* Otherwise, it is a request to remove a variable without altering it? */ + + return OK; + } + } + + /* Get a reference to the thread-private environ in the TCB.*/ + + sched_lock(); + rtcb = (FAR _TCB*)g_readytorun.head; + envp = rtcb->envp; + + /* Check if the variable alreay exists */ + + if ( envp && (pvar = env_findvar(envp, name)) != NULL) + { + /* It does! Do we have permission to overwrite the existing value? */ + + if (!overwrite) + { + /* No.. then just return success */ + + sched_unlock(); + return OK; + } + + /* Yes.. just remove the name=value pair from the environment. It will + * be added again below. Note that we are responsible for reallocating + * the environment buffer; this will happen below. + */ + + (void)env_removevar(envp, pvar); + } + + /* Get the size of the new name=value string. The +2 is for the '=' and for + * null terminator + */ + + varlen = strlen(name) + strlen(value) + 2; + + /* Then allocate or reallocate the environment buffer */ + + if (envp) + { + int alloc = envp->ev_alloc; + environ_t *tmp = (environ_t*)krealloc(envp, SIZEOF_ENVIRON_T(alloc + varlen)); + if (!tmp) + { + ret = ENOMEM; + goto errout_with_lock; + } + + envp = tmp; + envp->ev_alloc = alloc + varlen; + pvar = &envp->ev_env[alloc]; + } + else + { + envp = (environ_t*)kmalloc(SIZEOF_ENVIRON_T(varlen)); + if (!envp) + { + ret = ENOMEM; + goto errout_with_lock; + } + + envp->ev_crefs = 1; + envp->ev_alloc = varlen; + pvar = envp->ev_env; + } + + /* Now, put the new name=value string into the environment buffer */ + + sprintf(pvar, "%s=%s", name, value); + + /* Save the new environment pointer (it might have changed due to allocation or + * reallocation. + */ + + rtcb->envp = envp; + sched_unlock(); + return OK; + +errout_with_lock: + sched_unlock(); +errout: + errno = ret; + return ERROR; +} + +#endif /* CONFIG_DISABLE_ENVIRON */ + + + |